Inspirion 8600 blue screen from my house

it works just fine at my office but for some reason at home the only thing i can get to work is in safe mode. just replaced the hard drive and reinstalled windows xp by the geek squad at best buy. when i take it back to them, it works fine boots up normally. they cant seem to find out what the problem is, I have taken it back to them three times but still have the same problem.