I’ve found this approach helpful in many cases.
Boot the machine in Safe Mode (w/NO network support) and log in as administrator.
Then go to the folder(s) in question and take ownership, and force that change to propagate. Because the permissions can be tightly locked by some of these pests, you may have to do multiple iterations before you’ve really got full control over that portion of the file system again.
Hope that helps,
I believe that your computer system has been already infected with viruses. Specifically, the system files are already infected that is why it shows weird results. You have to immediately back up your important files before your entire system gets paralyze.