What's with these people saying dumb things?

anyway, right now i am running win98, and i am installing a dual boot with Ubuntu on my machine, and i'm a little nervous because i don't have my Windows disc, so if something goes wrong, i'm screwed. will this disc work if i accidentally overwrite Windows? i don't have any valuable files on that machine so that is of no concern, but it is the only Windows machine in the house (i'm a Mac guy) and i need to run some windows apps. will this disc work as a backup plan?