Have you tried this link? Error Codes: 64C & 66C (Can't install updates) - Microsoft Answers
It is for those specific error codes.
Also, it may not help, but tyy opening an elevated command prompt ( click the start button, in the search box type cmd, in the only entry that appears, right click it and select 'run as administrator') In the command prompt window copy/paste this sfc /scannow
it is a system file checker that may detect any corrupted or missing system files and attempt to repair them.