|I think I would first run AVG or Malware bytes and identify just what and if there is a boot virus.|
If you research this you will find people who say "Remove hard drive ...flash the bios in dos....then wipe the drive"
If you screw up the flash....your computer is toast.
If you screw up the hd wipe ...go buy a new hard drive.
I use Dericks Boot and Nuke.....but it can kill a hd .1in 10.
Find out what virus is on the system first. It could just be a registry problem. You may have had a false positive running disk manager.