Question : XP install over Vista - format hangs at 63%

I am working on a Dell PC that came with Vista Home Premium and the customer wants XP.
After collecting the data, I ran the dell XPSP3 install CD and when it came to the partition to install it on it failed.
I reinstalled and when it came to the partition I chose to format.  It stopped at 63 %, tried again, same thing.
Deleted and recreated the C partition and formatted, same thing, failed at 63%.
There is a D recovery partition (Vista Home) that I did not delete.

Answer : XP install over Vista - format hangs at 63%

It could be a bad hard disk.  
Boot the Dell to the the recovery partition and start the diagnostics on the drive.  Run the full diagnostic.