explorer.exe, System Tray, hang

[Val]

Well, I finally tracked the problem down to the "SSDP
Discovery Service". Either something new on my Home
Network (I recently installed an old 3Com Ethernet Card
on another PC and a Belkin UPS on mine) is causing a
problem, or the latest updates from Microsoft caused it
(I downloaded the service some time before I started
having problems). Now that I have made a work-around by
disabling the offending service, I need to find a
permanent fix.
>-----Original Message-----
>When I boot Windows XP it comes up with the System Tray
>locked. Clicking on "Start" does nothing, Right-
Clicking
>on the Tray does nothing, Clicking on icons in the Tray
>does nothing. I get no response from the System Tray at
>all. It seems all other functions work - I can start
>programs from the icons on my desktop, CTL-ALT-DEL
brings
>up the Task Manager, etc. Then, when I shutdown (from
>Task Manager) I get "explorer.exe not responding" and
>have to end the task for the system to shutdown. I have
>restored from a previous "checkpoint" but it does no
>good. Any ideas, hints, tips???
>.
>