There are Dell diagnostics on the hard drive accessed by F12
at power on. First step would be to run a complete diagnostic and see if anything shows up.
Try all / any USB ports (you most likely have) -
To repair XP you will need both the DELL XP reinstallation disc and either a DVD, or CD drive.
If you reside in the US and are the registered owner of the computer, a disc containing the factory-installed operating system specific to your system, available from HERE
: Dell may charge for the disc.
All Drivers and Downloads for your system can be found at http://support.dell.com/support/downloads
If you are considering an operating system reinstall, please Click Here
for an alternative.