What OS was on the "old" disk? Maybe your mate formatted the old disk before giving it to you. (to get rid of all the secrets he had on there)
When you try and boot up, have you got a CD in the CD drive? If its not the XP disk, then it wants the XP disk so that it can boot up.
If you have nothing in the CD drive when starting up, then I don’t know what the problem is….but wish you luck.