You can set the resolution manually by editing one of the games' .ini files.
\My Documents\My Games\Crysis\game.ini
Edit the lines:
r_Width =
r_Height =
you can find this information, plus a boatload of tweaking tips here:
http://www.tweakguides.com/Crysis_1.htmlHe also has a Crysis Warhead guide, though 95% of it is the same.
Geez, I don't think I ever played those on multi-monitor, and I never did finish Warhead. I shall ahve to reinstall it this week. Last i played i had a single display on a 8800gtx.