The call of duty board is missing so i posted it here (It works for other games too, but this is the best solution to record videos on cod mw2).
Kay, here we go
First of all u have to download WeGame
Download Links: Rapidshare | 4Shared
Then, u have to get on their site, www.WeGame.com and create an account
U dont need to add your real info, but u have to remember the login id and your pass
After registering open WeGame and install it.
Hit next, and add the account you just created on their site and click Login existing account
Choose the directory to save the videos and click next
Choose a hotkey for recording (I have F9)
And chose quality (High Definition is better obviously.)
Choose a directory to save your screenshots and click next
Choose a hotkey to take screenshots and click next
Choose a browser if u want to use it for flash game recordings or if u dont want choose disabled and click next.
Click start WeGame
Login with your account and you are ready ^^ happy recording
Video guide:
http://www.youtube.com/watch?v=UBAR5g-z2m8
Credits for screenshots - Me
Credits for video - Clayman
@The end it have a HQ video so u can see how it records, its a good alternative like fraps