I got tired of looking at that Windows Messenger icon in the tool tray so I found a way to stop it from loading.
You need to edit the registry so be careful!
In addition, you may want to disable the Windows Messenger Service, which sounds similar although it serves a different function. Still, it's another source of possible spyware and viruses so you might as well disable it.
This program from all around super-tech guru Steve Gibson will do the trick. http://www.grc.com/stm/shootthemessenger.htm
I decided to remove the Notifyalert.exe program from a Dell PC which appeared to be slowing it down. The program is part of the Dell Support program that you can normally remove under Add / Remove Programs. Apparently this only works for version 3. If you have version 2 of Dell Support then the Add / Remove programs function can fail.
If you have version 2 of the Dell Support program, you need to reinstall the program and then remove it. Go to http://support.dell.com/ and do a search on "uninstall dell support" which will give you a link to the uninstall program.