Hi RJCF,
·Provide the exact error message or error code you are receiving when trying to boot to the computer?
Try booting the computer using Last known good configuration, you may refer the below link for the steps:
How to start your computer by using the Last Known Good Configuration feature in Windows XP:http://support.microsoft.com/kb/307852
If that does not help, you may have to contact the manufacturer of the computer for support options.
For further troubleshooting steps, you may refer the below link: How to recover from a corrupted registry that prevents Windows XP from starting: http://support.microsoft.com/kb/307545
Regards:
Samhrutha G S - Microsoft Support.
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