0xc000021a after Windows Updates


If, after you apply Windows Updates and reboot your computer, you get a blue screen with code 0xc000021a here are a couple of things that you can try:

Corrupt Driver Signature Catalog Files

  1. When the systems boots up, press F8 repeatedly until you get the Advanced Boot Option Screen
  2. Choose the option "Disable Driver Signature Enforcement"
  3. If the system boots up then you most likely have corrupt driver signature catalog files. To check which drivers are not signed you can use sigverif

Corrupt Registry Entries

  1. When the systems boots up, press F8 repeatedly until you get the Advanced Boot Option Screen (or boot with a Windows DVD)
  2. Choose the Repair Your Computer option
  3. Open Command Prompt
  4. Replace the SYSTEM and SOFTWARE registry hives by running the following commands (assuming OsDrive as C:\ below but it may differ on your system):
    1. cd C:\Windows\System32\config
    2. ren SYSTEM SYSTEM.old
    3. ren SOFTWARE SOFTWARE.old
    4. copy C:\Windows\System32\config\RegBack\SYSTEM C:\Windows\System32\config\
    5. copy C:\Windows\System32\config\RegBack\SOFTWARE C:\Windows\System32\config\
  5. Reboot system

 

Comments (2)

  1. Ed says:

    Question is after applying windows Updates, why would there be reboot issues now and not before. Surely, Windows Update wouldn’t allow unsigned drivers [excluding the corruption].

    1. Hi Ed,

      You are correct. Unsigned drivers are not permitted. What I am trying to cover is a couple of steps to try in case corruption occurs after the updates are installed. We usually do not see it until we reboot.
      This is not to say that Updates can corrupt the registry of the signature files, but there may be other applications that can scan or change these files when we are installing the updates thus leading to the corruption. Most often I’ve seen AV software that quarantine or delete the signature files.

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