Advanced troubleshooting for Windows boot problems

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Try our Virtual Agent - Information technology can aid you quickly identify and prepare common Windows boot issues.

Note

This article is intended for utilize by support agents and Information technology professionals. If you're looking for more general information nearly recovery options, see Recovery options in Windows 10.

Summary

There are several reasons why a Windows-based figurer may have issues during startup. To troubleshoot boot problems, showtime determine in which of the following phases the reckoner gets stuck:

Phase Boot Procedure BIOS UEFI
1 PreBoot MBR/PBR (Bootstrap Code) UEFI Firmware
2 Windows Kick Manager %SystemDrive%\bootmgr \EFI\Microsoft\Boot\bootmgfw.efi
iii Windows Bone Loader %SystemRoot%\system32\winload.exe %SystemRoot%\system32\winload.efi
4 Windows NT Bone Kernel %SystemRoot%\system32\ntoskrnl.exe

  1. PreBoot: The PC's firmware initiates a power-on self test (Mail) and loads firmware settings. This pre-boot process ends when a valid organisation disk is detected. Firmware reads the principal boot record (MBR), and then starts Windows Boot Manager.

  2. Windows Kicking Manager: Windows Kick Manager finds and starts the Windows loader (Winload.exe) on the Windows kicking partition.

  3. Windows operating system loader: Essential drivers required to offset the Windows kernel are loaded and the kernel starts to run.

  4. Windows NT OS Kernel: The kernel loads into memory the system registry hive and other drivers that are marked as BOOT_START.

    The kernel passes control to the session manager process (Smss.exe) which initializes the organisation session, and loads and starts the devices and drivers that aren't marked BOOT_START.

Here'due south a summary of the boot sequence, what will be seen on the display, and typical boot problems at that point in the sequence. Before you start troubleshooting, you have to understand the outline of the kick process and display status to ensure that the event is properly identified at the start of the engagement. Select the thumbnail to view it larger.

Diagram of the boot sequence flowchart.

Each phase has a different approach to troubleshooting. This article provides troubleshooting techniques for problems that occur during the offset 3 phases.

Note

If the computer repeatedly boots to the recovery options, run the following command at a command prompt to intermission the cycle:

Bcdedit /set {default} recoveryenabled no

If the F8 options don't piece of work, run the following command:

Bcdedit /set {default} bootmenupolicy legacy

BIOS stage

To decide whether the system has passed the BIOS phase, follow these steps:

  1. If there are any external peripherals connected to the computer, disconnect them.

  2. Check whether the hard disk drive light on the physical computer is working. If it's not working, this dysfunction indicates that the startup process is stuck at the BIOS phase.

  3. Printing the NumLock primal to come across whether the indicator light toggles on and off. If it doesn't toggle, this dysfunction indicates that the startup process is stuck at BIOS.

    If the system is stuck at the BIOS phase, there may exist a hardware problem.

Boot loader stage

If the screen is blackness except for a blinking cursor, or if yous receive i of the following mistake codes, this status indicates that the boot procedure is stuck in the Kick Loader phase:

  • Boot Configuration Information (BCD) missing or corrupted
  • Boot file or MBR corrupted
  • Operating arrangement Missing
  • Kick sector missing or corrupted
  • Bootmgr missing or corrupted
  • Unable to kick due to system hive missing or corrupted

To troubleshoot this trouble, use Windows installation media to showtime the calculator, press Shift + F10 for a command prompt, so use whatsoever of the post-obit methods.

Method i: Startup Repair tool

The Startup Repair tool automatically fixes many common problems. The tool besides lets yous quickly diagnose and repair more complex startup problems. When the calculator detects a startup problem, the computer starts the Startup Repair tool. When the tool starts, it performs diagnostics. These diagnostics include analyzing startup log files to determine the crusade of the problem. When the Startup Repair tool determines the cause, the tool tries to set the problem automatically.

To practise this task of invoking the Startup Repair tool, follow these steps.

  1. Get-go the organization to the installation media for the installed version of Windows. For more information, see Create installation media for Windows.

  2. On the Install Windows screen, select Next > Repair your computer.

  3. On the Cull an pick screen, select Troubleshoot.

  4. On the Advanced options screen, select Startup Repair.

  5. Subsequently Startup Repair, select Shutdown, and then plow on your PC to run into if Windows can boot properly.

The Startup Repair tool generates a log file to help yous understand the startup problems and the repairs that were made. You can find the log file in the post-obit location:

%windir%\System32\LogFiles\Srt\Srttrail.txt

For more information, see Troubleshoot blue screen errors.

Method 2: Repair Boot Codes

To repair kicking codes, run the following command:

              BOOTREC /FIXMBR

To repair the boot sector, run the following command:

              BOOTREC /FIXBOOT

Note

Running BOOTREC together with Fixmbr overwrites just the principal boot code. If the corruption in the MBR affects the partition tabular array, running Fixmbr may non fix the trouble.

Method 3: Fix BCD errors

If you lot receive BCD-related errors, follow these steps:

  1. Scan for all the systems that are installed. To practice this pace, run the following control:

                      Bootrec /ScanOS

  2. Restart the calculator to check whether the problem is fixed.

  3. If the problem isn't stock-still, run the following commands:

                      bcdedit /export c:\bcdbackup  attrib c:\kicking\bcd -r -s -h  ren c:\kick\bcd bcd.old  bootrec /rebuildbcd

  4. Restart the system.

Method 4: Supersede Bootmgr

If methods ane, 2 and 3 don't fix the problem, supervene upon the Bootmgr file from bulldoze C to the System Reserved partition. To practice this replacement, follow these steps:

  1. At a command prompt, modify the directory to the System Reserved partition.

  2. Run the attrib command to unhide the file:

                      attrib -r -s -h

  3. Navigate to the system drive and run the same command:

                      attrib -r -s -h

  4. Rename the bootmgr file equally bootmgr.old:

                      ren c:\bootmgr bootmgr.old

  5. Navigate to the system drive.

  6. Copy the bootmgr file, and then paste information technology to the Arrangement Reserved partition.

  7. Restart the reckoner.

Method 5: Restore organization hive

If Windows can't load the organisation registry hive into memory, yous must restore the system hive. To do this step, use the Windows Recovery Environs or use the Emergency Repair Deejay (ERD) to copy the files from the C:\Windows\System32\config\RegBack directory to C:\Windows\System32\config.

If the problem persists, you lot may want to restore the system state fill-in to an culling location, and then retrieve the registry hives to be replaced.

Kernel Phase

If the system gets stuck during the kernel phase, yous feel multiple symptoms or receive multiple mistake letters. These mistake letters include, just aren't limited to, the following examples:

  • A Stop error appears after the splash screen (Windows Logo screen).

  • Specific error code is displayed. For example, 0x00000C2 , 0x0000007B , or inaccessible boot device.

    • Advanced troubleshooting for Stop error 7B or Inaccessible_Boot_Device
    • Advanced troubleshooting for Event ID 41 "The organisation has rebooted without cleanly shutting downwardly first"

  • The screen is stuck at the "spinning bike" (rolling dots) "system busy" icon.

  • A blackness screen appears later on the splash screen.

To troubleshoot these problems, try the post-obit recovery boot options one at a time.

Scenario 1: Try to showtime the computer in Safety mode or Last Known Good Configuration

On the Advanced Boot Options screen, effort to beginning the computer in Safe Manner or Safe Mode with Networking. If either of these options works, utilise Event Viewer to help identify and diagnose the cause of the boot problem. To view events that are recorded in the result logs, follow these steps:

  1. Use one of the post-obit methods to open up Event Viewer:

    • Go to the Commencement menu, select Administrative Tools, and then select Event Viewer.

    • First the Event Viewer snap-in in Microsoft Direction Console (MMC).

  2. In the panel tree, expand Consequence Viewer, and then select the log that you lot desire to view. For example, choose System log or Application log.

  3. In the details pane, open the issue that yous want to view.

  4. On the Edit card, select Copy. Open up a new document in the programme in which you lot want to paste the event. For case, Microsoft Word. Then select Paste.

  5. Use the up arrow or downwardly arrow primal to view the description of the previous or next consequence.

Clean boot

To troubleshoot problems that affect services, practise a clean boot by using System Configuration (msconfig). Select Selective startup to exam the services one at a time to determine which ane is causing the problem. If you tin can't find the crusade, attempt including system services. Still, in well-nigh cases, the problematic service is tertiary-party.

Disable any service that yous find to be faulty, and try to commencement the reckoner again by selecting Normal startup.

For detailed instructions, see How to perform a clean boot in Windows.

If the computer starts in Disable Driver Signature way, first the computer in Disable Driver Signature Enforcement mode, and and so follow the steps that are documented in the following commodity to determine which drivers or files crave driver signature enforcement: Troubleshooting boot problem caused by missing driver signature (x64)

Note

If the figurer is a domain controller, try Directory Services Restore manner (DSRM).

This method is an important step if y'all meet Finish error "0xC00002E1" or "0xC00002E2"

Examples

Warning

Serious problems might occur if you modify the registry incorrectly by using Registry Editor or by using another method. These bug might crave that you reinstall the operating arrangement. Microsoft can't guarantee that these problems can be solved. Change the registry at your ain risk.

Error code INACCESSIBLE_BOOT_DEVICE (STOP 0x7B)

To troubleshoot this Terminate fault, follow these steps to filter the drivers:

  1. Go to Windows Recovery Surround (WinRE) past putting an ISO disk of the system in the disk drive. The ISO should be of the same version of Windows or a subsequently version.

  2. Open the registry.

  3. Load the system hive, and proper name it test.

  4. Under the following registry subkey, check for lower filter and upper filter items for non-Microsoft drivers:

    HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Class

  5. For each tertiary-party driver that you lot locate, select the upper or lower filter, and then delete the value data.

  6. Search through the whole registry for similar items. Process every bit advisable, and then unload the registry hive.

  7. Restart the server in Normal way.

For more than troubleshooting steps, see Advanced troubleshooting for Finish error 7B or Inaccessible_Boot_Device.

To fix bug that occur later you install Windows updates, check for awaiting updates by using these steps:

  1. Open a Control Prompt window in WinRE.

  2. Run the control:

                      DISM /paradigm:C:\ /get-packages

  3. If in that location are any pending updates, uninstall them by running the post-obit commands:

                      DISM /image:C:\ /remove-package /packagename: name of the package  DISM /Prototype:C:\ /Cleanup-Image /RevertPendingActions

    Try to start the computer.

If the computer doesn't outset, follow these steps:

  1. Open a control prompt window in WinRE, and start a text editor, such as Notepad.

  2. Navigate to the organisation drive, and search for windows\winsxs\awaiting.xml.

  3. If the pending.xml file is found, rename the file equally awaiting.xml.old.

  4. Open the registry, so load the component hive in HKEY_LOCAL_MACHINE as examination.

  5. Highlight the loaded test hive, and then search for the pendingxmlidentifier value.

  6. If the pendingxmlidentifier value exists, delete it.

  7. Unload the test hive.

  8. Load the system hive, name information technology test.

  9. Navigate to the following subkey:

    HKEY_LOCAL_MACHINE\System\ControlSet001\Services\TrustedInstaller

  10. Change the Start value from i to iv.

  11. Unload the hive.

  12. Endeavor to start the computer.

If the Stop error occurs belatedly in the startup process, or if the Stop error is notwithstanding existence generated, you can capture a retentiveness dump. A practiced retention dump can help determine the root cause of the Finish error. For more than data, see Generate a kernel or complete crash dump.

For more than data most page file bug in Windows 10 or Windows Server 2016, see Introduction to page files.

For more than information well-nigh Stop errors, see Advanced troubleshooting for Stop error or blue screen error issue.

Sometimes the dump file shows an error that'southward related to a driver. For example, windows\system32\drivers\stcvsm.sys is missing or corrupted. In this instance, follow these guidelines:

  • Check the functionality that's provided by the driver. If the driver is a 3rd-political party kicking driver, make sure that you understand what it does.

  • If the commuter isn't important and has no dependencies, load the arrangement hive, and and then disable the driver.

  • If the stop error indicates system file corruption, run the arrangement file checker in offline manner.

    • To practise this activeness, open WinRE, open a command prompt, and then run the following command:

                            SFC /Scannow /OffBootDir=C:\ /OffWinDir=C:\Windows

      For more information, see Using organization file checker (SFC) to ready issues.

    • If there's deejay abuse, run the bank check deejay command:

                            chkdsk /f /r

  • If the Cease error indicates general registry corruption, or if yous believe that new drivers or services were installed, follow these steps:

    1. Offset WinRE, and open a command prompt window.
    2. Commencement a text editor, such equally Notepad.
    3. Navigate to C:\Windows\System32\Config\.
    4. Rename the all five hives past appending .old to the proper name.
    5. Copy all the hives from the Regback binder, paste them in the Config folder, and then try to showtime the estimator in Normal mode.