Problems with crysis warhead starting up

Okay so I got a new computer for my birthday but It had a crapy graphics card. So I ordered and ati 4870 1gb from newegg. While I was waiting I decided to play crysis warhead on the computer I got it ran it but cound only go about 20 fps on low settings. Now that I got the card I try to load a game of warhead and it will get to about 94% then freeze. Please help.

Specs for PC:

Intel core 2 quad 2.5 ghz

4gb of ram

Radeon 4870 1gb

Update your graphics card driver, if it's not the latest and try to reinstall the game.