To do only a reformat on a hard drive will not eliminate a virus. As long as there is one partition on the drive, the virus can respawn itself. Even the best anti-viral software may not be effective at complete removal.
The only sure cleansing is as I suggested.. delete any existing partitions, then exit the setup program with none formed, and shut down for more than one minute. Restart, and you are 99.9% assured of a 'sanitized' drive.
If the drive still has partitions, then the MBR has been corrupted. A specific DOD format is needed. WIKI: Data Remanence
has a comparable program.
F@H.. to solve mankind's maladies.. in our lifetimes!