Does anybody else have a problem where TF2 gets to the loading screen (before the menu and after the steam logo) but then stops loading and crashes. Dont know what to do ?????? Help me please!!!!!!

First, open the steam "games"-list, right-click on TF2->Properties->Set launch options...
and type the parameter "-novid" without the quotes in there.
If it doesnt fix the problem it still reduces the time you spend waiting to see if you're gonna crash.

Second, defrag your Steam GCFs on a regular basis.
(Make sure you exit steam first and dont exit the defrag-progress until its done or you might get corrupted files -> reinstall)

Both those help with lotsa weird problems and should be done anyway.
Give it a try.

For that specific error, what did it say in the box? Little more information prease.

Thanks