43b7af74_vices_List___Overclockers_Club__Notes
[Service Name] Fast User Switching Compatibility [Recommended Setting] Manual/Disable [Notes] 
This service allows you to quickly change the user that is logged in Windows. If you're the only user that users your computer then you can disable this service.
Windows XP Services Removal Guide » Page 2 - Windows Services List - Overclockers Club
Notes