Had a 'phone call from son in England. Running XP Pro. Picked up a Trojan horse. AVG up to date and removed it. However, every time he boots up he gets a splash screen with Trojan horse downloader written on it. He cancels the screen and nothing else is wrong. He doesn't know the trojan's name. I seem to remember having read somewhere that you have to switch off system restore before deleting. Is this correct?