I had to assist a customer of mine today who had allowed his Win7 system to upgrade to Win10
The PC was suffering frequent total lockups with no obvious cause - other than the upgrade.
No event log clues or crash dumps were found - so hunt the bug or downgrade back to Win7 ??
I downgraded him back to Win7 and used GRC Never10 to keep him there.
Fixed a few corrupted applications and all was well
Except for one thing - the Task Scheduler had masses of corrupted task error messages
Apparently the revert from Win10 back to Win7 is known to cause this problem
https://social.technet.microsoft.com/Forums/windowsserver/en-US/80e4f83d-1529-4405-b8e3-d1d636f8b71cI found a special utility that scans and repairs the Win7 Task Scheduler Library
https://repairtasks.codeplex.com/The reviews look really good - might be worth a look if you encounter this issue
Doug Collins - Computer Support Engineer - London UK