Got the stop error:
Stop: 0x0000007B (0x80403BA0,0xC0000034,0x00000000,0x00000000)
This happens only on restart, any ideas?
Problem solved: Installed service pack 1 for vista.
He had service pack 2 on the pc when the problem started. I think it was more than one problem, but it's working now so I'm happy.
Thanks a lot for the posts guys