I bought a couple of used toshiba satellite pros and one has a hard drive with a norton operating system made special for the DOD. I'd like to format it and install windows. If I could get to the dos system, I could do it, but can't seem to locate it anywhere. It has an opening screen requiring a password etc, but can move around a little in it. Is there someway like holding a key down while booting to go straight to dos? Thank you.