Update: did a clean install of W7, ran WU, and upgraded to W10 using the "standard" WU method. All is finally good.

Ran that, along with another FixIt, neither worked. They both find issue(s) and "fix" them, but WU still fails. Repeated runs of the tools keep finding and "fixing" the same errors. I'm using the...

it actually didn't at all... ended up installing 7 (again!) after 10 failed to recognize the GenuineToken.xml file... Oddly, WU is still not functioning. When the WU service is running, the CPU goes...

This'll work, thanks. Odd that a proper upgrade is impossible here, but thank you very much for the workaround. :)

I'm using the method in step 5 (Windows Update is totally broken on this machine), and it keeps asking me to enter my Windows 10 key. The installer will check for updates, then immediately ask for a...