Before the boot environment is loaded, computers start up from hardware and firmware. Windows desktop operating systems do things a bit differently from Windows Server operating systems when it comes to power-state management features. In Windows desktops, turning off a computer and shutting down a computer are separate tasks. By default, when you turn off a computer running a Windows desktop operating system, the computer enters standby mode. When entering standby mode, the operating system automatically saves all work, turns off the display, and enters a low power-consumption mode with the computer’s fans and hard disks stopped. The state of the computer is maintained in the computer’s memory. When the computer wakes from standby mode, its state is exactly as it was when you turned off your computer.

You can turn off a computer running a Windows desktop operating system and enter standby mode by tapping or clicking the Settings charm, tapping or clicking Power, and then tapping or clicking Sleep. To wake the computer from the standby state, you can press the power button on the computer’s case or a key on the computer’s keyboard. Moving the mouse also wakes the computer.

If you install Windows 8.1 or Windows Server 2012 R2 on a mobile computer, the computer’s power state can be changed by closing the lid. By default with Windows 8.1, the computer enters the standby state when you close the lid. By default with Windows Server 2012 R2, the computer doesn’t change its power state when you close or open the lid, but you can configure the server to shut down when you close the lid.

There are, however, a few gotchas with the power button and the standby state in Windows desktop operating systems. The way the power button works depends on the following:

You can determine exactly how the power options are configured on a computer running Windows by tapping or clicking the Settings charm, tapping or clicking Control Panel, and tapping or clicking Power Options. The available options depend on the type of computing device.

Whether you are working with a Windows desktop operating system or a Windows Server operating system when trying to diagnose and resolve startup problems, be sure to keep in mind that power-state management capabilities are provided by the hardware but are enabled by the operating system. Because of this, to diagnose and resolve boot issues fully, you must look at the computer’s hardware and software, including the following items:

To understand the hardware aspects of boot issues better, let’s dig in and take a look at Advanced Configuration and Power Interface (ACPI). A computer’s motherboard/chipset, firmware, and operating system must support ACPI for the advanced power-state features to work. There are many types of motherboards/chipsets. Although older motherboards/chipsets might not be updateable, most of the newer ones have updateable firmware. Chipset firmware is separate from and different from the computer’s underlying firmware interface.

Currently, there are three prevalent firmware interfaces:

A computer’s BIOS, EFI, or UEFI programming provides the hardware-level interface between hardware components and software. Like chipsets themselves, BIOS, EFI, and UEFI can be updated. ACPI-aware components track the power state of the computer. An ACPI-aware operating system can generate a request for the system to be switched into a different ACPI mode. BIOS, EFI, or UEFI responds to enable the requested ACPI mode.

ACPI 4.0 was finalized in June 2009, and ACPI 5.0 was finalized in December 2011. Computers manufactured prior to this time will likely not have fully compliant firmware, and you will probably need to update the firmware when a compatible revision becomes available. In some cases, and especially with older hardware, you might not be able to update a computer’s firmware to make it fully compliant with ACPI 4.0 or ACPI 5.0. For example, if you are configuring the power options, and you don’t have minimum and maximum processor-state options, the computer’s firmware isn’t fully compatible with ACPI 3.0 and likely will not fully support ACPI 4.0 or ACPI 5.0 either. Still, you should check the hardware manufacturer’s website for firmware updates.

ACPI defines active and passive cooling modes. These cooling modes are inversely related to each other:

Power policy includes upper and lower limits for the processor state, referred to as the maximum processor state and the minimum processor state, respectively. These states are implemented by using a feature of ACPI 3.0 and later versions called processor throttling, and they determine the range of currently available processor performance states that Windows can use. By setting the maximum and minimum values, you define the bounds for the allowed performance states, or you can use the same value for each to force the system to remain in a specific performance state. Windows reduces power consumption by throttling the processor speed. For example, if the upper bound is 100 percent and the lower bound is 5 percent, Windows can throttle the processor within this range as workloads permit to reduce power consumption. In a computer with a 3 GHz processor, Windows would adjust the operating frequency of the processor between 0.15 GHz and 3.0 GHz.

Processor throttling and related performance states were introduced with early Windows operating systems, but these early implementations were designed for computers with discrete-socketed processors and not for computers with processor cores. As a result, they are not effective in reducing the power consumption of computers with logical processors. Beginning with Windows 7 and Windows Server 2008 R2, Windows reduces power consumption in computers with multicore processors by using a feature of ACPI 4.0 called logical processor idling and by updating processor-throttling features to work with processor cores.

Logical processor idling is designed to ensure that Windows uses the fewest processor cores for a given workload. Windows accomplishes this by consolidating workloads onto the fewest cores possible and suspending inactive processor cores. When additional processing power is required, Windows activates inactive processor cores. This idling functionality works in conjunction with the management of process performance states at the core level.

ACPI defines processor performance states, referred to as p-states, and processor idle sleep states, referred to as c-states. Processor performance states include P0 (the processor or core uses its maximum performance capability and can consume maximum power), P1 (the processor or core is limited below its maximum and consumes less than maximum power), and Pn (where state n is a maximum number that is processor dependent, and the processor or core is at its minimal level and consumes minimal power while remaining in an active state).

Processor-idle sleep states include C0 (the processor or core can execute instructions), C1 (the processor or core has the lowest latency and is in a nonexecuting power state), C2 (the processor or core has longer latency to improve power savings over the C1 state), and C3 (the processor or core has the longest latency to improve power savings over the C1 and C2 states).

Windows saves power by putting processor cores in and out of appropriate p-states and c-states. On a computer with four logical processors, Windows might use p-states 0 to 5, where P0 allows 100 percent usage, P1 allows 90 percent usage, P2 allows 80 percent usage, P3 allows 70 percent usage, P4 allows 60 percent usage, and P5 allows 50 percent usage. When the computer is active, logical processor 0 would likely be active with a p-state of 0 to 5, and the other processors would likely be at an appropriate p-state or in a sleep state.

ACPI 4.0 and ACPI 5.0 define four global power states. In G0, the working state (in which software runs), power consumption is at its highest, and latency is at its lowest. In G1, the sleeping state (in which software doesn’t run), latency varies with the sleep state, and power consumption is less than the G0 state. In G2 (also referred to as S5 sleep state), the soft off state when the operating system doesn’t run, latency is long, and power consumption is very near zero. In G3, the mechanical off state (in which the operating system doesn’t run), latency is long, and power consumption is zero. There’s also a special global state, known as S4 nonvolatile sleep, in which the operating system writes all system context to a file on nonvolatile storage media, allowing the system context to be saved and restored.

Within the global sleeping state, G1, are the sleep-state variations summarized in Table 3-1. S1 is a sleeping state in which the entire system context is maintained. S2 is a sleeping state similar to S1 except that the CPU and system-cache contexts are lost, and control starts from a reset. S3 is a sleeping state in which all CPU, cache, and chipset contexts are lost, and hardware maintains the memory context and restores some CPU and L2 cache configuration context. S4 is a sleeping state in which it is assumed that the hardware has powered off all devices to reduce power usage to a minimum, and only the platform context is maintained. S5 is a sleeping state in which it is assumed that the hardware is in a soft off state, in which no context is maintained, and a complete boot is required when the system wakes.

Motherboard chipsets support specific power states. For example, a motherboard might support the S0, S1, S4, and S5 states, but it might not support the S2 or S3 states. In Windows operating systems, the sleep power transition refers to switching off the system to a Sleep or Hibernate mode, and the wake power transition refers to switching on the system from a Sleep or Hibernate mode. The Sleep and Hibernate modes allow users to switch off and switch on systems much faster than the regular shutdown and startup processes.

Thus, a computer is waking up when the computer is transitioning from the OFF state (S5) or any sleep state (S1–S4) to the ON state (S0), and the computer is going to sleep when the computer is transitioning from the ON state (S0) to the OFF state (S5) or sleep state (S1–S4). A computer cannot enter one sleep state directly from another because it must enter the ON state before entering any other sleep state. Sleep and hibernate are disabled in Windows Server.

On most computers, you can enter BIOS, EFI, or UEFI during boot by pressing F2 or another function key. When you are in firmware, you can open the Power screen or a similar screen to manage ACPI and related settings.

Power settings you might see include the following:

Because Intel and AMD also have other technologies to help reduce startup and resume times, you might also see the following power settings:

Enhanced Intel SpeedStep Technology (EIST or SpeedStep) allows the system to adjust processor voltage and core frequency dynamically, which can result in decreased average power consumption and decreased average heat production. When EIST or a similar technology is enabled and in use, you see two processor speeds on the System page in Control Panel. The first speed listed is the specified speed of the processor. The second speed is the current operating speed, which should be less than the first speed. If Enhanced Intel SpeedStep Technology is off, the processor speeds will be equal. Advanced Settings for Power Options under Processor Power Management can also affect how this technology works. Generally speaking, although you might want to use this technology with a Windows desktop operating system, you won’t want to use it with a Windows Server operating system.

Intel Quick Resume Technology Driver (QRTD) allows an Intel Viiv technology–based computer to behave like a consumer electronic device with instant on/off after an initial boot. Intel QRTD manages this behavior through the Quick Resume mode function of the Intel Viiv chipset. Pressing the power button on the computer or a remote control puts the computer in the Quick Sleep state, and the computer can Quick Resume from sleep when you move the mouse, press an on/off key on the keyboard (if available), or press the sleep button on the remote control. Quick Sleep mode is different from standard sleep mode. In Quick Sleep mode, the computer’s video card stops sending data to the display, the sound is muted, and the monitor LED indicates a lowered power state on the monitor, but the power continues to supply vital components on the system such as the processor, fans, and so on. Because this technology was originally designed for earlier Windows operating systems, it does not work in many cases with later Windows desktop operating systems and generally should not be used with Windows Server operating systems. You might need to disable this feature in firmware to enable a Windows desktop operating system to sleep and resume properly.

After you look at the computer’s power settings in firmware, you should also review the computer’s boot settings in firmware. Typically, you have a list of bootable devices and can select which one to boot. You also might be able to configure the following boot settings:

As with power settings, your computer might not have these exact labels, but the labels should be similar. You need to optimize these settings for the way you plan to use the computer. In most cases, with server hardware, you’ll only want to enable Boot To Hard Disk Drive. The exception is when you use BitLocker Drive Encryption. With BitLocker, you’ll want to enable Boot To Removable Devices, USB Boot, or both to ensure that the computer can detect the USB flash drive with the encryption key during the boot process.

The Startup And Recovery dialog box controls the basic options for the operating system during startup. You can use these options to set the default operating system, the time to display the list of available operating systems, and the time to display recovery options when needed. Whether you start a computer to different operating systems or not, you want to optimize these settings to reduce the wait time during startup and, in this way, speed up the startup process.

You can access the Startup And Recovery dialog box by completing the following steps:

You can use the System Configuration utility (Msconfig.exe) to fine-tune the way a computer starts. Typically, you use this utility during troubleshooting and diagnostics. For example, as part of troubleshooting, you can configure the computer to use a diagnostic startup so only basic devices and services are loaded.

The System Configuration utility is available on the Tools menu in Server Manager. You can also start the System Configuration utility by pressing the Windows key, typing msconfig.exe in the Apps Search box, and pressing Enter. As shown in Figure 3-3, this utility has a series of tabs with options.

Use the General tab options to configure the way startup works. Start your troubleshooting and diagnostics efforts on this tab. You can use these options to perform a normal startup, diagnostic startup, or selective startup. After you restart the computer and resolve any problems, access the System Configuration utility again, select Normal Startup on the General tab, and then tap or click OK.

Figure 3-3. Performing a diagnostic or selective startup as part of troubleshooting.

Use the Boot tab options, shown in Figure 3-4, to control the way the individual startup-related processes work. You can configure the computer to start in one of various Safe Boot modes and set additional options, such as No GUI Boot. If after troubleshooting you find that you want to keep these settings, you can select the Make All Boot Settings Permanent check box to save the settings to the boot configuration startup entry.

Figure 3-4. Fine-tuning the boot options.

Tapping or clicking the Advanced Options button on the Boot tab opens the BOOT Advanced Options dialog box shown in Figure 3-5. In addition to being able to lock PCI, detect the correct hardware abstraction layer (HAL), and enable debugging, you can use the advanced options to do the following:

If you suspect services installed on a computer are causing startup problems, you can quickly determine this by choosing a diagnostic or selective startup on the General tab. After you identify that services are indeed causing startup problems, you can temporarily disable services using the Services tab options and then reboot to see whether the problem goes away. If the problem no longer appears, you might have pinpointed it. You can then permanently disable the service or check with the service vendor to see whether an updated executable is available for the service. As shown in Figure 3-6, you disable a service by clearing the related check box on the Services tab.

Figure 3-5. Setting advanced boot options as necessary to help troubleshoot specific types of problems.

Figure 3-6. Disabling services to pinpoint the source of a problem.

Similarly, if you suspect applications that run at startup are causing problems, you can quickly determine this by using the options on the Startup tab. You disable a startup application by clearing the related check box on the Startup tab. If the problem no longer appears, you might have pinpointed the cause of it. You can then permanently disable the startup application or check with the software vendor to see whether an updated version is available.

The BCD store contains multiple entries. On a BIOS-based computer, you see the following entries:

Windows Boot Manager is itself a boot loader application. There are other boot loader applications, including the following:

You can view and manage the BCD store directly by using BCD Editor (BCDEdit.exe). BCD Editor is a command-line utility. You can use it to view the entries in the BCD store by following these steps:

Table 3-2 summarizes commands you can use when you are working with the BCD store. These commands enable you to:

Computers can have system and nonsystem BCD stores. The system BCD store contains the operating system boot entries and related boot settings. Whenever you work with the BCD Editor, you will be working with the system BCD store.

On a computer with only one operating system, the BCD entries will look similar to those in Entries in the BCD store on a single-boot computer. As the listing shows, the BCD store for this computer has two entries: one for Windows Boot Manager and one for Windows Boot Loader. Here, the Windows Boot Manager calls the boot loader, and the boot loader uses Winload.exe to boot Windows Server 2012 R2.

Windows Boot Manager
--------------------
identifier              {bootmgr}
device                  partition=F:
description             Windows Boot Manager
locale                  en-US
inherit                 {globalsettings}
bootshutdowndisabled    Yes
default                 {current}
resumeobject            {fcb757a2-7476-11e1-8312-bd48864d9bf1}
displayorder            {current}
toolsdisplayorder       {memdiag}
timeout                 30
Windows Boot Loader
-------------------
device                  partition=C:identifier              {current}
path                    Windowssystem32winload.exe
description             Windows Server 2012 R2
locale                  en-US
inherit                 {bootloadersettings}
recoverysequence        {fcb757a2-7476-11e1-8312-bd48864d9bf1}
recoveryenabled         Yes
allowedinmemorysettings 0x15000075
osdevice                partition=C:
systemroot              Windows
resumeobject            {fcb757a2-7476-11e1-8312-bd48864d9bf1}
nx                      OptOut

BCD entries for Windows Boot Manager and Windows Boot Loader have similar properties, which are summarized in Table 3-3.

When you are working with the BCD store and BCD Editor, you see references to well-known identifiers, summarized in Table 3-4, and GUIDs. When a GUID is used, it has the following format, where each N represents a hexadecimal value:

{NNNNNNNN-NNNN-NNNN-NNNN-NNNNNNNNNNNN}

Such as:

{fcb757a2-7476-11e1-8312-bd48864d9bf1}

The dashes that separate the parts of the GUID must be entered in the positions shown.

When additional operating systems are installed on a computer, the BCD store for it has additional entries for each additional operating system. For example, the BCD store might have one entry for Windows Boot Manager and one Windows Boot Loader for each operating system.

When a previous operating system is installed on a computer, the BCD store has three entries: one for Windows Boot Manager, one for Windows Legacy OS Loader, and one for Windows Boot Loader. Generally, the entry for Windows Legacy OS Loader will look similar to Sample Legacy OS Loader entry.

Windows Legacy OS Loader
------------------------
identifier:             {ntldr}
device:                 partition=C:
path:                   
tldr
description:            Earlier version of Windows

Although Windows Boot Manager, Windows Legacy OS Loader, and Windows Boot Loader are the primary types of entries that control startup, the BCD also stores information about boot settings and boot utilities. The Windows Boot Loader entry can have parameters that track the status of boot settings, such as whether No Execute (NX) policy is set for Opt In or Opt Out. The Windows Boot Loader entry also can provide information about available boot utilities such as the Memory Diagnostics utility.

To view the actual value of the GUIDs needed to manipulate entries in the BCD store, type bcdedit /v at an elevated command prompt.

Using BCD Editor, you can create a new, nonsystem BCD store by using the following command:

bcdedit /createstore StorePath

Here, StorePath is the actual folder path to where you want to create the nonsystem store, such as:

bcdedit /createstore c:
on-syscd

On an EFI system, you can temporarily set the system store device by using the /sysstore command. Use the following syntax:

bcdedit /sysstore StoreDevice

Here, StoreDevice is the actual device identifier store, such as:

bcdedit /sysstore C:

BCD Editor provides separate commands for importing and exporting the BCD store. You can use the /export command to export a copy of the system BCD store’s contents to a specified folder. Use the following command syntax:

bcdedit /export StorePath

Here, StorePath is the actual folder path to which you want to export a copy of the system store, such as:

bcdedit /export c:ackupcd.dat

To restore an exported copy of the system store, you can use the /import command. Use the following command syntax:

bcdedit /import ImportPath

Here, ImportPath is the actual folder path from which you want to import a copy of the system store, such as:

bcdedit /import c:ackupcd.dat

On an EFI system, you can add /clean to the import to specify that all existing firmware boot entries should be deleted. Here is an example:

bcdedit /import c:ackupcd.dat /clean

BCD Editor provides separate commands for creating, copying, and deleting entries in the BCD store. You can use the /create command to create identifier, application, and inherit entries in the BCD store.

As shown previously, in Table 3-4, BCD Editor recognizes many well-known identifiers, including {dbgsettings} used to create a debugger settings entry, {ntldr} used to create a Windows Legacy OS entry, and {ramdiskoptions} used to create a RAM disk additional options entry. To create identifier entries, you use the following syntax:

bcdedit /create Identifier /d "Description"

Here, Identifier is a well-known identifier for the entry you want to create, such as:

bcdedit /create {ntldr} /d "Earlier Windows OS Loader"

You also can create the following entries for specific boot-loader applications:

Use the following command syntax:

bcdedit /create /application AppType /d "Description"

Here, AppType is one of the previously listed application types, such as:

bcdedit /create /application osloader /d "Windows 8.1"

You can delete entries in the system store by using the /delete command and the following syntax:

bcdedit /delete Identifier

If you are trying to delete a well-known identifier, you must use the /f command to force deletion, such as:

bcdedit /delete {ntldr} /f

By default, when using the /delete command, the /cleanup option is implied, and this means BCD Editor cleans up any other references to the entry being deleted. This ensures that the data store doesn’t have invalid references to the identifier you removed. Because entries are also removed from the display order, this can result in a different default operating system being set. If you want to delete the entry and clean up all other references except the display order entry, you can use the /nocleanup command.

After you create an entry, you then need to set additional entry option values as necessary. Here is the basic syntax for setting values:

bcdedit /set Identifier Option Value

Here, Identifier is the identifier of the entry to be modified, Option is the option you want to set, and Value is the option value, such as:

bcdedit /set {current} device partition=d:

To delete options and their values, use the /deletevalue command with the following syntax:

bcdedit /deletevalue Identifier Option

Here, Identifier is the identifier of the entry to be modified, and Option is the option you want to delete, such as:

bcdedit /deletevalue {current} badmemorylist

To view the BCD entries for all boot utilities and values for settings, type bcdedit /enum all /v at an elevated command prompt. This command enumerates all BCD entries regardless of their current state and lists them in Verbose mode. The additional entries will look similar to those in Additional entries in the BCD store on a single-boot computer (shown later in the chapter). Each additional entry has a specific purpose and lists values that you can set, including the following:

Resume from Hibernate
---------------------
identifier              {fcb757a2-7476-11e1-8312-bd48864d9bf1}
device                  partition=C:
path                    Windowssystem32winresume.exe
description             Windows Resume Application
locale                  en-US
inherit                 {1afa9c49-16ab-4a5c-901b-212802da9460}
recoverysequence        {fcb757a2-7476-11e1-8312-bd48864d9bf1}
recoveryenabled         Yes
allowedinmemorysettings 0x15000075
filedevice              partition=C:
filepath                hiberfil.sys
debugoptionenabled      No
Windows Memory Tester
---------------------
identifier              {b2721d73-1db4-4c62-bf78-c548a880142d}
device                  partition=F:
path                    ootmemtest.exe
description             Windows Memory Diagnostic
locale                  en-US
inherit                 {7ea2e1ac-2e61-4728-aaa3-896d9d0a9f0e}
badmemoryaccess         Yes
EMS Settings
------------
identifier              {0ce4991b-e6b3-4b16-b23c-5e0d9250e5d9}
bootems                 Yes
Debugger Settings
-----------------
identifier              {4636856e-540f-4170-a130-a84776f4c654}
debugtype               Serial
debugport               1
baudrate                115200
AM Defects
-----------
identifier              {5189b25c-5558-4bf2-bca4-289b11bd29e2}
Global Settings
---------------
identifier              {7ea2e1ac-2e61-4728-aaa3-896d9d0a9f0e}
inherit                 {4636856e-540f-4170-a130-a84776f4c654}
                        {0ce4991b-e6b3-4b16-b23c-5e0d9250e5d9}
                        {5189b25c-5558-4bf2-bca4-289b11bd29e2}
Boot Loader Settings
--------------------
identifier              {6efb52bf-1766-41db-a6b3-0ee5eff72bd7}
inherit                 {7ea2e1ac-2e61-4728-aaa3-896d9d0a9f0e}
                        {7ff607e0-4395-11db-b0de-0800200c9a66}
Hypervisor Settings
-------------------
identifier              {7ff607e0-4395-11db-b0de-0800200c9a66}
hypervisordebugtype     Serial
hypervisordebugport     1
hypervisorbaudrate      115200
Resume Loader Settings
----------------------
identifier              {1afa9c49-16ab-4a5c-901b-212802da9460}
inherit                 {7ea2e1ac-2e61-4728-aaa3-896d9d0a9f0e}
Device options
--------------
identifier              {5824ba7c-acee-11e1-ba52-cfa3fef36259}
description             Windows Recovery
ramdisksdidevice        partition=C:
ramdisksdipath          Recovery5824ba7b-acee-11e1-ba52-cfa3fef36259oot.sdi

Table 3-5 summarizes key options that apply to entries for boot applications (BOOTAPP). Because Windows Boot Manager, Windows Memory Diagnostics, Windows OS Loader, and Windows Resume Loader are boot applications, these options apply to them as well.

Table 3-6 summarizes key options that apply to entries for Windows OS Loader (OSLOADER) applications.

Data Execution Prevention (DEP) is a memory-protection technology. Windows Server 2012 and Windows Server 2012 R2 are the first versions of Windows Server that require a processor that supports DEP. Windows Server 2012 and Windows Server 2012 R2 will not install on computers that aren’t DEP-enabled.

With DEP enabled, the computer’s processor marks all memory locations in an application as nonexecutable unless the location explicitly contains executable code. If code is executed from a memory page marked as nonexecutable, the processor can raise an exception and prevent the code from executing. This behavior prevents malicious application code, such as virus code, from inserting itself into most areas of memory.

For computers with processors that support the No Execute (NX) page protection feature, you can configure the operating system to opt in to NX protection by setting the nx parameter to OptIn or opt out of NX protection by setting the nx parameter to OptOut. Here is an example:

bcdedit /set {current} nx optout

When you configure NX protection to OptIn, DEP is turned on only for essential Windows programs and services. This is the default. When you configure NX protection to OptOut, all programs and services—not just standard Windows programs and services—use DEP. Programs that shouldn’t use DEP must be specifically opted out. You can also configure NX protection to be always on or always off using AlwaysOn or AlwaysOff, such as:

bcdedit /set {current} nx alwayson

Processors that support and opt in to NX protection must be running in PAE mode. You can configure PAE by setting the PAE parameter to Default, ForceEnable, or ForceDisable. When you set paeState to Default, the operating system will use the default configuration for PAE. When you set paeState to ForceEnable, the operating system will use PAE. When you set paeState to ForceDisable, the operating system will not use PAE. You can set DebugOptionEnabled to true or false. Here is an example:

bcdedit /set {current} pae default

You can change the display order of boot managers associated with a particular Windows operating system by using the /displayorder command. The syntax is:

bcdedit /displayorder id1 id2 ... idn

Here, id1 is the operating system identifier of the first operating system in the display order, id2 is the identifier of the second, and so on. Thus, you could change the display order of the operating systems identified in these BCD entries:

Windows Boot Loader
-------------------
identifier              {fcb757a2-7476-11e1-8312-bd48864d9bf1}
Windows Boot Loader
-------------------
identifier              {16b857b4-9e02-11e0-9c17-b7d085eb0682}

You can do this by using the following command:

bcdedit /displayorder {16b857b4-9e02-11e0-9c17-b7d085eb0682}
{fcb757a2-7476-11e1-8312-bd48864d9bf1}

You can set a particular operating system as the first entry by using /addfirst with /displayorder, such as:

bcdedit /displayorder {fcb757a2-7476-11e1-8312-bd48864d9bf1} /addfirst

You can set a particular operating system as the last entry by using /addlast with /displayorder, such as:

bcdedit /displayorder {fcb757a2-7476-11e1-8312-bd48864d9bf1} /addlast

You can change the default operating system entry by using the /default command. The syntax for this command is:

bcdedit /default id

Here, id is the operating system ID in the boot loader entry. Thus, you could set the operating system identified in this BCD entry as the default:

Windows Boot Loader
-------------------
identifier             {fcb757a2-7476-11e1-8312-bd48864d9bf1}

You can do this by using the following command:

bcdedit /default {fcb757a2-7476-11e1-8312-bd48864d9bf1}

If you want to use a pre–Windows Server 2008 operating system as the default, use the identifier for the Windows Legacy OS Loader. The related BCD entry looks like this:

Windows Legacy OS Loader
------------------------
identifier              {466f5a88-0af2-4f76-9038-095b170dc21c}
device                  partition=C:
path                    
tldr
description             Earlier Microsoft Windows Operating System

Following this, you could set Ntldr as the default by entering the following:

bcdedit /default {466f5a88-0af2-4f76-9038-095b170dc21c}

You can change the timeout value associated with the default operating system by using the /timeout command. Set the /timeout command to the desired wait time in seconds, such as:

bcdedit /timeout 30

To boot automatically to the default operating system, set the timeout to zero seconds.

Occasionally, you might want to boot to a particular operating system one time and then revert to the default boot order. To do this, you can use the /bootsequence command. Follow the command with the identifier of the operating system to which you want to boot after restarting the computer, such as:

bcdedit /bootsequence {14504de-e96b-11cd-a51b-89ace9305d5e}

When you restart the computer, the computer will set the specified operating system as the default for that restart only. Then, when you restart the computer again, the computer will use the original default boot order.