Ok, after I saw about 13 posts on the same thing, AO crashing and entire system locking up, I decided to try and help.
I've replied to other posts on the same topic, but I can't find all of you that are having this problem.
If you are crashing in missions and other places, to the point where you entire system locks up and has to be rebooted to play again, or you crash to the "Blue Screen of Death", you might be having a software conflict with Anarchy Online and the Window ME operating system. The only sure-fire fix I've found so far, after trying multiple things, in various ways for 5+ days is that WinME is screwed up when running AO after the last patch and you need to install a new OS or upgrade to WinXP. This all just started recently, correct? (this bug not the other ones )
So, if you can, go to the store, get WinXP, reformat and install WinXP. You should really do it anyway since WinME is a crappy OS. The worst Microsoft has ever released. If you compare the amount of critical updates WinME has needed in the last few years to the amount any other Microsoft OS has needed, it almost triple. Seems like they pulled a FC and released it before they shoulda .
Anyway, if you aren't running WinME and are still having this problem...reply here and let us know. We are trying to isolate this to try and help everyone.
Thanks for your time and I hope this helps.
PS - The upgrade package for WinXP, if you are already a WinME user, should cost you roughly $100. Or just borrow a friends copy