Nero Back-It-Up Problem

I have a boot disk for this program that works fine in my computer but on my friends computer, the disc goes through all of the regular processes until it displays an error saying that it needs the second floppy disc (remember this is a CD disc and works fine under the same conditions as my computer.

Both COmputers are Athlon Dual Core machines with WIndows XP (not that that should make any difference since its a boot disc). Mine is custom built by me. Hers is an Acer Aspire.

ANy help is appreciated.