Windows & BSOD · critical

How to fix0x00000100

LOADER_BLOCK_MISMATCH

What this error means

LOADER_BLOCK_MISMATCH is a critical-severity Windows operating system issue. A Loader Block Mismatch occurs when the boot loader (Winload.efi) passes a system parameters block to the Windows kernel that is incompatible or corrupted. Commonly caused by corrupted boot records, memory faults, or unstable overclocking. It's also often linked to failed storage driver installation. Follow the steps below to fix it.

Before you begin

Save open work and back up important files. Use instructions for your exact device and software version. If Windows cannot start, see the startup guide.

Work through these checks

0 of 4 complete
01Rebuild the Boot Configuration Data (BCD) using recovery USB
  1. Rebuild the Boot Configuration Data (BCD) using recovery USB
What to expect

Check whether the original symptom still occurs.

If it does not help

Continue only if this check applies to your device. Consult its manufacturer if you are unsure.

Browse related errors
02Clear CMOS or disable XMP/EXPO memory profiles
  1. Clear CMOS or disable XMP/EXPO memory profiles
What to expect

Check whether the original symptom still occurs.

If it does not help

Continue only if this check applies to your device. Consult its manufacturer if you are unsure.

Browse related errors
03Run Startup Repair from Windows Recovery
  1. Run Startup Repair from Windows Recovery
What to expect

Check whether the original symptom still occurs.

If it does not help

Continue only if this check applies to your device. Consult its manufacturer if you are unsure.

Browse related errors
04Run SFC scan offline in Command Prompt
  1. Run SFC scan offline in Command Prompt
What to expect

Check whether the original symptom still occurs.

If it does not help

Continue only if this check applies to your device. Consult its manufacturer if you are unsure.

Browse related errors

Possible causes

  • Damaged or corrupted EFI bootloader files (winload.efi)
  • Unstable memory overclocking (XMP/EXPO) or timing
  • Corrupted Windows registry system hive
  • Failed storage driver installation