i was running the game fine in window mode until i crash. i then started the game up again and now it says it cant support window mode. im fairly sure i didnt change anything in between.

Sometimes i had to restart my pc, not just the game to get window mode to work again. Don't know why but you might wish to give it a try; good luck.

Not sure why you would even want to run a FPS in a window, but rebooting should fix this issue.

Not sure if it'll work, but some games can be forced into windowed mode by adding -w behind the target for the icon you're using.

yeah...i found out that since that day ive had to restart my pc after playing nv 4 awhile 2 get my video card working again; btw, im doing window mode cuz if the game freezes i can force quit the game w/o restarting pc.