So it’s day 4 messing with this damned old laptop (3 years old so it’s not really old) trying to upgrade it to Windows 10. It keeps hanging at about 85%. I get the error:
0xC1900101-0x40021
I run this setupdiag.exe that I downloaded to see why it is stopping, and it can’t find any failure signatures. Searching online and seeing many, MANY people having upgrade issues, I tried several things… updated BIOS, ran Windows 7 updates several times, updated drivers. It still freezes with no evident (using setupdiag).
Trying to be patient and just keep trying. It’s the extra laptop with no real purpose anymore, but would be good to reuse.