Need some information (Ima noob, o well =] )

Alright guys, I found the key to my CoD4 disc, thanks to Joshcarr, but now I have a different predicament. I tried playing just normal campaign with the lowest graphical settings, and It lags. BAD! But what I dont understand is why...Ive gone to a site that says i can run it, but wtf! Need some information as to how much fps i should be getting, and other helpful things. Here's screenies of the site saying i can run it.





Anyone that is good with computers and such, got any advice?

first, try running it with admin. if that doesnt work try closing all programs. the next thing i suggest is to reinstall. if none of those work try to return the game saying the game has a defect and if that doesn't work i don't know what to try =l