I have Windows XP on a Dell Dimension 2400.  The mouse is a Dell USB optical mouse.  XP is using a generic driver (HID Interface).  When I install XP Service Pack 2 the mouse stops working.  It appears that there is no power going to the mouse as the red led goes off as the Windows system is loaded.  It is on during the initial DOS boot up.  I tried different USB ports and a Logitech USB optical mouse with no luck in the results.  Even tried installing Logitech Mouseware and using their mouse and no results.  I updated the BIOS to A05 - no change.   Any suggestions? 

Message Edited by ajmarton on 07-12-200610:56 PM