KB5034441 Fails with 0x80070643? It's the Recovery Partition, Not Windows Update

Windows Update keeps offering KB5034441 (the January 2024 Windows Recovery Environment update), and it keeps failing with:

“0x80070643 — ERROR_INSTALL_FAILURE”

…then re-offers itself on the next check, forever.

Why almost every guide gets this wrong: the top results tell you to run the Update troubleshooter, clear the SoftwareDistribution cache, or hide the update. None of that addresses the actual cause. KB5034441 needs 250 MB of free space inside your WinRE recovery partition to install — and the default Windows 10 recovery partition (often ~500 MB, already mostly full) doesn’t have it. Microsoft confirmed it will not auto-resize the partition for you; you have to do it. The 0x80070643 code here really means insufficient disk space in the recovery partition (CBS_E_INSUFFICIENT_DISK_SPACE), not a corrupt update.

First decide: do you even need to fix it?

KB5034441 hardens BitLocker against a WinRE bypass. If you don’t use BitLocker drive encryption, this update is low-risk to simply leave uninstalled. If you’d rather stop the nagging without resizing partitions, that’s a legitimate choice — pause updates or hide KB5034441. If you do use BitLocker, or you just want it gone properly, resize the partition below.

The real fix: enlarge the WinRE partition

This involves repartitioning the disk, so back up first and follow Microsoft’s official command sequence (KB5028997) for your exact layout. The standard flow (admin Command Prompt):

1. Disable WinRE and check its location:

   reagentc /disable
   reagentc /info

2. Shrink the OS (C:) partition to free ~250 MB using diskpart (list disk → select disk → list partition → select the Windows partition → shrink desired=250 minimum=250).
3. Delete the old recovery partition and create a larger one in diskpart, matching the partition type for your disk:
   • GPT disks: recreate with set id="de94bba4-06d1-4d40-a16a-bfd50179d6ac" and gpt attributes=0x8000000000000001.
   • MBR disks: create a primary partition with id=27.
   • Then format quick fs=ntfs label="WinRE".
4. Re-enable WinRE:

   reagentc /enable
   reagentc /info

   Confirm it reports Enabled.
5. Re-run Windows Update — KB5034441 now installs.

The exact diskpart IDs and the offsets differ between GPT and MBR/BIOS systems. Use the verbatim commands in Microsoft’s KB5028997 article for your disk type — getting the partition GUID/type wrong is the one step that can leave WinRE non-bootable.

FAQ

Will resetting Windows Update fix it? No. Clearing SoftwareDistribution or running the troubleshooter does nothing here because the download isn’t the problem — there’s simply no room in the recovery partition for the payload.

Is 0x80070643 always this? No — 0x80070643 is a generic install-failure code. But when it’s specifically KB5034441 stuck and re-offered, the recovery-partition space cause is the documented one.

Can I just hide the update? Yes, if you don’t use BitLocker. It’s a recovery-environment hardening update; skipping it doesn’t affect day-to-day Windows. If other updates are also stuck, see reset Windows Update the right way.

Sources: Microsoft — KB5034441: Windows Recovery Environment update (Jan 9, 2024)