Windows 7 Ultimate 64 bit error on any instal or uninstal

It happens trying to uninstall or install a program or update. Some programs just do nothing. It might be "msiexec.exe Application error" or some other name. The computer had been shut down and unplugged for 5 weeks while I recovered from surgery. Now this started.
It starts with:
xxxxx Application error. The application was unable to start
correctly(0xC0000006).

I have tried System File Checker. It reported some files fixed and some that could not be fixed.

Any help greatly appreciated....