GUI doesn't load
I'm trying to troubleshoot an IBM system that doesn't load the Graphical User INterface. It's running windows XP Pro, and the user says it has a virus. I am able to run a sophos scan in Safe Mode with command prompt, and it says it doesn't detect any virus. When it boots to normal mode, it just has the desktop background pic, nothing else, no icons or task bar, but I am able to run programs through task manager(Ctrl, Alt, Del). I ran Internet Explorer and downloaded AVG anti-virus and did a scan, still nothing, no viruses. What's causing the GUI from running, is there a certain file that should be checked or what. Any ideas on how to fix this ?