I can't speak much for MSNM and Windows Messenger, as I have never run into a problem with both of those running.
But I can agree, that you should NOT have AVG and McAfee running. That's like putting two starving sumo wrestlers in a room, and covering the other person with bacon. They will give you false positives and attack eachother. Long story short, pick one, un-install the other.
After the system stalls and you have to reboot, I would check in the Event Viewer. I know I preach this a lot, but so many people don't realize the beauty of this tool. Sometimes, if the machine really crashes, it doesn't write to it, but it's a good place to start.
If the freeze has happened yet again, repeat what you did before. Disable everything and then go one-by-one. It sucks to do, I know, but maybe you have missed something. If you know for sure it doesn't happen after doing that, then it just means something is running that is causing problems. It may be tedious, and take time, but that's the catch 22 to fixing an issue sometimes.
Of course, if you don't want to deal with it, backup, format, re-install, and move on
Vanquished said:
Back in the msconfig startup tab, do you need to enable the things u use?
Microsoft will automatically enable the things it needs to run...
In the MSCONFIG "Startup" tab, NOTHING in there is needed by Microsoft to run. You don't have to check/enable anything, only devices which you would like to be running. Anything Microsoft needs to run would be listed under the "Services" tab, one to the left. If you go in there, as I mentioned above, you should check the box to "hide all Microsoft Services", this way whatever else you turn off won't prevent your box from booting.