Generally memory errors are more likely than hard disk ones - in addition to a hard disk diagnostic, run memtest. You can get both off of the ultimate boot CD. Just google it.
Disk error... Burn a Hiren Boot CD an run a scandisk on that HDD. it can also be the case that you have another HDD/Card Reader/USB Drive/Printer with Card Reader that is giving you trouble. Sometimes Running the XP instalation CD until it reaches the HDD selection menu and shutting also solves the problem
Generally memory errors are more likely than hard disk ones - in addition to a hard disk diagnostic, run memtest. You can get both off of the ultimate boot CD. Just google it.