Troubleshooting Windows boot problems for IT Pros

Applies to: Windows 10Windows Server 2016Windows 8.1 More


There are several reasons why a Windows-based computer may hang during startup. To troubleshoot boot problems, first determine in which of the following phases the computer gets stuck:

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

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

Bcdedit /set {default} recoveryenabled no

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

Bcdedit /set {default} bootmenupolicy legacy

BIOS phase

To determine 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 is not working, this indicates that the startup process is stuck at the BIOS phase.
  3. Press the Num Lock key to see whether the indicator light toggles on and off. If it does not, this indicates that the startup process is stuck at BIOS.

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

Boot loader phase

If the screen is completely black except for a blinking cursor, or if you receive one of the following error codes, this indicates that the boot process is stuck in the Boot Loader phase:

  • Boot Configuration Data (BCD) missing or corrupted
  • Boot file or MBR corrupted
  • Operating system Missing
  • Boot sector missing or corrupted
  • Bootmgr missing or corrupted
  • Unable to boot due to system hive missing or corrupted

To troubleshoot this problem, use Windows installation media to start the computer, press Shift+F10 for a command prompt, and then use any of the following methods.

    Kernel phase

    If the system gets stuck during the kernel phase, you experience multiple symptoms or receive multiple error messages. These include, but are not limited to, the following:

    • A Stop error appears after the splash screen (Windows Logo screen).
    • Specific error code is displayed. For example, "0x00000C2," "0x0000007B," "inaccessible boot device," and so on. (To troubleshoot the 0x0000007B error, see Error code INACCESSIBLE_BOOT_DEVICE (STOP 0x7B).)
    • The screen is stuck at the "spinning wheel" (rolling dots) "system busy" icon.
    • A black screen appears after the splash screen.

    To troubleshoot these problems, try the following recovery boot options one at a time.