Xp upgrade - cd issues

An upgrade to XP wasn't working this morning with the pc giving various error messages - Setup was unable to verify drive C, Setup cannot copy the file: driver.cab. At this point it had damaged the w2k installation enough that the previous installation would not boot. A chkdsk from the recovery console would just reboot the pc. Booting to BartCD I was able to run defrag and a chkdsk with no problems found. I tried different installation media and still got the same problem. I searched for a BIOS upgrade but couldn't find anything useful so I then swapped the cd drive itself and it is now working (or at least it is most of the way through the upgrade).