AOMEI Partition Manager would not start because of a "side by side" error involving Microsoft.VC80.MFC" version="8.0.50727.762.
Go to event viewer and check the problem.
Looked to me like a 2005 Visual C problem even though it was installed.
So, I went to:
https://www.techpowerup.com/download/visual-c-redistributable-runtime-package-all-in-one/
https://www.techpowerup.com/download/visual-c-redistributable-runtime-package-all-in-one/
which has a zip of all versions. I reinstalled 2005 and bingo. Thank you TechPowerUp.
In 42 years of PC usage this is the first "side by side" error I've seen.