I have not had to reformat any of the pc, but my advice is a tool like malwarebytes and a good antivirus like avg, is avoid unpleasant surprises.
I know it's a touchy subject, but many antivirus installed a fix, one fix modifies the registry and the program itself, so you're not protected by much I think.
for example, pro malwarebytes avoid entering any paguina that may contain some malicious content to protect well in advance of any infection.
and a live cd or usb knowing you have to remove, as in this case the file named in the title of the post, are very useful.
in any case also can recover the hard drive you want and if you want then do a clean install and new.