Hi,
Thank you for sharing your question. I understand about that update error message on Windows 10: “We couldn’t complete the update, undoing changes.”
I get how annoying it is when updates keep failing, mainly since you’ve already tried running commands like chkdsk and sfc.
This issue usually happens because of messed-up system files or disk errors that stop Windows from doing the updates. Since sfc said it couldn’t fix some files and chkdsk gave a cyclic redundancy check error, try running DISM to fix the Windows image. Open Command Prompt as administrator and type this:
DISM /Online /Cleanup-Image /RestoreHealth
When DISM is done, run sfc /scannow again to check the repairs. If it still messes up, check your disk health with chkdsk /r, or try the Windows Update Troubleshooter in Settings > Update & Security > Troubleshoot. If things are terrible, you might want to do an in-place upgrade repair using the newest Windows 10 ISO; that can fix corruption issues without losing your files.
I hope this helps.
Best Regads,
Noel