My rule of thumb: if you got a virus, repair enough to save data, backup, and wipe.
It sounds like whatever virus you had changed what program Windows opens your drives with to the reformat program. That's deep registry stuff there.
You may have to backup using a network if you can.
If you need help with the backup/reformat process, I'd be glad to walk you through it, but you will have a bit of reading to do if you don't know some parts.