freezes on boot ….

I am trying to repair an HP xt938 running Windows XP. The problem is that it freezes on boot and on safe boot it stops on amdagp.sys.
I tried recovering, reinstalling, destructive and non-destructive recovery . None would work.
I tried using a new XP to do a clean install and that workedfine, but I would rather not have to purchase a new xp for this computer. Is there anyway to resolve this problem from the recovery disks that they supply, without having to purchase a new XP cd? Are there any files that I can replace or download that would fix this issue. Any help is greatly appreciated.

Thanks,
Enbee