Well, I don't. Obviously one must clean his system from any virus BEFORE formatting anything, who knows if the format will be effective or if it will be a fake one modified by the Virus? But then, once the HD's BOTH internal and external ones are clean from virii, there is NOT one reason in the world to actually format anything. jaclaz Sorry my sequence isnt right. I mean. First: Scan your HDD with an virus scanner. Second: Make a backup Last: Format and restore your HDD. EDIT: So Spoiledbrat is right.