Ok your problem is that you UNINSTALLED Messenger (I presume we are talking the chat client). What you need to do is keep it on your system but DISABLE it. Fire up Explorer | Program Files and find Messenger, then RIGHT click on the file and RENAME to something like MessengerDIS. This will stop the Messenger client loading but WITHOUT the slowdown experienced in IE6, Outlook etc.
To disable Windows Messenger (the source of a lot of those annoying pop ups) type <services.msc> (without <>) into the run box and press enter. This will bring up the sevices applet. Scroll down to Messenger RIGHT click select PROPERTIES and DISABLE then press STOP. When in the services its a good idea to DISABLE all services that are not required, try here for a good list of services that can safely be disabled.
Once done you will have a much more secure, stable and faster OS. Hows that for value!!!