Hello I reformatted a friends hard drive (xp home) with

it plugged into my computer and it is now running fine.I unplugged it from mine and plugged it in hers and it boots to windows start up options.Regardless of which option I choose it restarts itself.I plugged it back into my computer and it is fine.I plugged my hard drive into her computer same restarting.I changed the cables and got the same result.I disabled the restart option when you use f8 and got the blue screen stop error. If one of the pins on the motherboard where the hard drive plugs in is bent,not broken,or loose cause this?Any help is appreciated.thanks