Corrupt XP backup

We have a laptop which blue screened. We managed to connect the hard drive as a slave to another system and ran the backup program which comes with Windows XP. The backup and verify worked ok, however when we have come to restore the data after running the recovery CD’s to re-build the laptop it is telling us that the backup contains unrecognisable data, and cannot be used.

IS THERE ANY WAY OF GETTING DATA OFF THIS BACKUP SET. THIS IS VERY URGENT!!!!