Disappearing Programmes

My son just downloaded XP Home Edition SP2, and suddenly IE, OE, AIM, MS Messenger, and other programmes that access the Internet boot but immediately disappear! The Internet connection is active (FTP and IRC work) and I’ve tried both Firewall ON and Firewall OFF. Task Manager shows the progs are still active, but they’re invisible!

Anybody ever seen anything like this????

Thanks, — David Turner