No new applications will launch, required logout/login

[Agro]

This is a very strange problem that I cannot figure out how to fix, other then formatting or re-installing Win2k over-top of my current installation (that may not even fix it, format would though).

My system will be working 100% perfectly.
Out of nowhere (between 15 minutes - 5 hours) I will not be able to launch any new programs. This includes all programs installed AND stuff such as Explorer, Control Panels, or even the Show Desktop button, etc.
All programs that are currently open still function perfectly and even quit perfectly.
To get things working again, I either have to logout/login or reboot.
I have tried End-Task'ing everything except explorer, and the problem persists.

What could be causing this? The system worked perfectly for months without this problem. I am unsure what program was installed that started this, or when, etc.

I -KNOW- I can format to fix this. Do you people have any suggestions?

System Is ...
ABIT KG7 Lite Motherboard
AMD Thunderbird 1.4GHz CPU
GeForce2 MX-200 32MB DDR Video Card
256MB Kingston PC2100 DDR Memory
SoundBlaster Ensoniq AudioPCI
3COM 3C905b Network Card
20GB Maxtor Drive
52X IDE CD
Windows 2000 Professional (Service Pack2 + all other updates from www.windowsupdate.com)
NVIDIA Detonator XP drivers
etc...

Any ideas what causes this?

 

[dexmanone]

Have you tried going thru your start up and removing anything that is not absolutely necessary? If this helps then add one by one back in and see if one is causing a conflict. Worth a shot.

 

[gritnugget]

Do you have any virus software running? Try to get some and run a full scan on your system with the latest dat files. If you endtask explorer and restart it what happens? Have you found anything on support.microsoft.com ?