It sounds like fast user switching is on and others users have failed to log off properly or close programs. This will slow your computer dramatically.
My computer (Windows XP, Dell Pentium four) has been running extremly slow, I have defraged, did a disk/hard drive clean up and emptied temp file bin. When checking the Windows application I have scvhost.exe running twice for both the System and the Network system. I also have iexplore running in duplicate under my user name, all other users are logged off when I have checked and found this. Please Help!!!
Thank you Kelly