Well, it sounds like the upgrade may have gone badly. I'd recommend you consider wiping the hard drive and starting over. For example, CCleaner is a well regarded application (I use it myself on every Windows 8.1 system I own).
However, you can try uninstalling MC completely and re-installing from scratch (it wasn't clear if you uninstalled it in your quest to delete things).
But, it sounds to me like you have OS level issues, and we likely won't be able to troubleshoot much beyond that.