run>cmd>sfc /scannow
Automated 'fix ma self' command, probably won't solve the problem but it gives you stable ground to work on, also chkdsk c: /f scheduled for startup.

The fix it apps from microsoft are also very good if they cater to your actual problem, otherwise worse then useless.

Combine with ccleaner for cleanup and maintenance, defrag for performance and the shutting down of redundent services for security and performence.
And for the love of all that is sacred have a working firewall and while you don't need always on antimalware, at least have 2 scanners installed for when the paranoia kicks in or you let someone touch your comp, including yourself.



Nothing beats automated maintenance and user competence, except the odd intentional attack and late night warezing session where you thought opening that exe was a good idea but you should know better.