This is the first time I ever thought my computer was truly kaput. New Gateway machine running that Windows Media Center... Anyway, Civ4 was in the process of an autosave when the screen locked up. Ctrl-Alt-Del wasn't doing anything, so I had to resort to unplugging the machine. I was just like, "Ok, not the end of the world, these things happen." But when I rebooted my machine and I got an error that said, "your config.sys file is corrupt or missing" and went on about how I'll have to get my system restore disks, yada, yada, yada... That definitely freaked me out. My computer wouldn't go any farther. After rebooting several times and scavenging for the receipt for the Best Buy Service Plan (I was finally happy I bought the silly service plan), I decided to give it one more try and it actually rebooted! I'm just hoping they take care of this crash problem in the patch.