TaskManager not responding in Windows XP

I am having Windows XP patched up completely (No SP2) and using Windows XP firewall and NAV 2002.

Though windows taskmanager works fine when the system boots up, after a few minutes, it fails to respond. When I press Ctrl Alt Del, the taskmgr icon comes up in the system tray, but the application fails to show up.

Also at these times, MS Office fails to respond and so does Explorer. Also I have peculiar problem all the time. I am not able to use the Win key to show the desktop or open the explorer or to run a command (Win+D, Win+E, Win+R). There is no response when I use these commands.

Win+U works fine (Utilities) though. there is no problem also when i use Win key to invoke the start menu.

 

Hmm.. Btw .. The keystroke combination for Taskman is Ctrl Shift Esc actually ... anyways ..
Download Process Explorer .. Does it work fine ..?

Btw .. I suspect you got parasites on your system.. Scan your system with updated virus definitions:
Panda ActiveScan
Stinger
Symantec System Check
Kaspersky

 

yup. checked everything, but could find nothing fishy except this odd behavior. I use updated NAV, Symantec System check, process explorer, autoruns, adaware and spybot. Installed all XP patches (except SP2).
I dont use IE.
Or could there be something with ctfmon.exe (MS Office 2003)