We have several users with Dell laptops running Windows XP, SP2. Every once in awhile, the laptops boot to a blank screen with an error that explorer.exe cannot start because uxtheme.dll is missing. We usually instruct the user how to use the Task Manager to connect to the VPN, and we copy uxtheme.dll to the machine, then start explorer.exe through the Run box. (We have one particular user who gets the error once a month or so.) My research says the error is connected with WinXP SP2. Has anybody else encountered this?