Hi, Jello.
What are you really trying to do? As Chris said, WinXP has a built-in way
to create an MS-DOS boot disk, but that probably won't help with WinXP
problems, especially if you are using NTFS. As Yves said, the WinXP CD-ROM
is bootable and will get you into the Recovery Console, from which you can
fix many basic problems.
But your Subject line says "Virus on boot". Do you have a virus? A boot
sector virus? Do you know the name of the virus?
The more you tell us, the more likely that we can help you do what you want
or need to do. Otherwise, we're trying to read your mind and you've given
us only a few apparently-contradictory clues. Your message and your screen
name remind me of the famous line about "trying to nail Jell-O to a tree".
:>{
RC