Wait is this true? Do you have a reference for this? (im just curious)
I can't find the source I had for that, but I remember the person that said it was a credible source (I believe he was a Microsoft MVP). I believe it to be true.
This may seem like a stupid question, but I'm an idiot when it comes to hardware... when you reformat isn't the old data still there but the computer just flags it as free space so it can be overridden? So couldn't a virus be resistant to reformatting?
If you do a quick format, the old data will technically be there, but the HD controller will return it as free space, so the virus couldn't rise from the dead. If you are really concerned you could do a full format, which is do a more complete formatting of the data.