do I need certain type of hard drive to back up DOS & Windows XP?
I need a portable back up of a DOS program on this old computer. Should I use a hard drive or can I use a USB flash drive?
Either one. It’s predicated on just how much data you have to back up. Cost per gigabyte is going to be lower on an external hard drive.
You could use either one, but USB flash drive will be easier since connection is so simple. You don’t even need to open up the computer, as you would to connect a non-USB hard drive.