Where can I get good hardware diagnostic tools for my laptop? Windows XP...

[Borgman]

...won't boot even in safe mode...? it's happened four times. it's as if the registry keeps getting corrupted. With the Windows CD I can recover the registry to a previous point...but I think it may be a bad sector on the disk where the boot/registry info is kept.

i don't know I'm grasping at straws here but what would you do? I need to confirm if it's a hardware problem.