Service pack 1 actually changed it to disabled by default. If you want to make sure its deactivated go to start>run> type "msconfig" without the quotes. at the far right you'll see a tab for startup. Look for a box for windows messenger and make sure its unchecked. While you're there you might as well uncheck a couple of more programs that don't need to start at boot up. All they do is slow you down and sap system resources. Quicktime, office, winamp, things like that. If you don't recognise it, don't touch it, or google it to see if its nesessary to have it start up with the computer. I've had clients who had 30 or 40 programs starting with every time they booted up, and just unchecking some little boxes cut their load time in half. After you restart the computer a box will come up talking about using selective start up or something along those lines. Uncheck the box that says "show this screen each time I boot up" then hit OK. Cheers,
Shawn