probabbly cause by windows corrupted or other things like Nightstalker1993 said.. if it bcoz of widnows corrupted,i think it bcoz of ur windows are not isntalled properly.. try to refromat back ur pc by using other CDROm drive (as u said earlier ur CDROm are trying hard to read the CD when u wanna install the XP) .. or it maybe ur CDROm are didnt have enough power feeding on it.. try to use a single mainly power cable directly feed to the CDROm when u try to installed it.. hope it works..