When I right click on my desktop, the mouse cursor changes to the hour glass and then just sits there.  Any further action is ignored, other than CTRL-ALT-DEL which brings up the appropriate window.  I can shut down from there (can't from the Start Button - no response there) or by pushing in and holding the power button on the computer. 

 

No recent installations or changes to the configuration. 

 

The computer is a Dimension 8100 running Windows XP Pro with all SP and updates current.

 

Any clues to the cause and/or remedy is appreciated.

 

Roy