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Error 0x80070643

How to Fix Windows Installer/Defender Error 0x80070643

Fix time: 25 mins Difficulty: Hard 0 views Updated: July 2026

Fix installer and .NET updates failure showing error 0x80070643 on Windows.

Symptoms

  • Update KB5034441 (or similar) fails with code 0x80070643

Common Causes

  • Insufficient Recovery Partition size for Windows RE security updates

Step-by-Step Solutions

Method 1: Resize Recovery Partition (WinRE)

Many cumulative security updates require at least 250MB free in the WinRE partition to install.

  1. Open Command Prompt as Admin. Disable WinRE: reagentc /disable
  2. Use diskpart tool to shrink primary C: volume by 500MB and expand Recovery partition.
  3. Re-enable WinRE: reagentc /enable

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Frequently Asked Questions

Yes, you can hide this update package using Microsoft Show/Hide tool if you don't use BitLocker.