Switching users on XP kills my PC.
 

I need to run programs in the background on another XP user account while I use my XP main account.

When I try to switch between my two accounts(either when I use the switch users function or switch users manually from the logon screen) my PC completely crashes. My display turns off and I have to hard reboot my computer(it is unresponsive to Ctrl+Alt+Del). Both of the accounts work individually.

I looked this up online and I think that the Terminal Services service is responsible for controlling user switching. However, its status is on and startup type is manual. It should be running.

I am running Ultramon(dual monitors on DVI), Kerio Personal Firewall 2.1.5 and AntiVir. All other background programs are part of windows.

WTF do I do now? I'm looking for both permanent solutions to fixing the problems and a temporary solution to run programs in the background without having them popup in my face all the time(they pop up randomly and disrupt my web browsing etc).