Windows & BSOD · critical

How to fix0x80070643

Windows Update Error 0x80070643 (WinRE size too small)

What this error means

Windows Update Error 0x80070643 (WinRE size too small) is a critical-severity Windows operating system issue. This error is triggered when Windows Update fails to install the recovery partition update (often KB5034441) due to the Windows Recovery Environment (WinRE) partition size being too small. It's also often linked to system servicing stack corruption. Use the steps below to track down and fix the cause.

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 3 complete
01Manually resize the WinRE partition to allocate at least 250MB of additional space.
  1. Manually resize the WinRE partition to allocate at least 250MB of additional space.
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
02Re-enable WinRE using reagentc command line utility.
  1. Re-enable WinRE using reagentc command line utility.
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
03Reset Windows Update component files.
  1. Reset Windows Update component files.
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

  • Insufficient free space in the Windows Recovery Environment (WinRE) partition.
  • Corrupted recovery image files.
  • System servicing stack corruption.