Is the latest Internet Explorer version installed?
Are your graphics and sound drivers up to date?
Did you let the game run the directx updater on installation?
As a first measure try reducing the graphics quality and please give us a dxdiag log.
changing the graphics quality
Start the game.
Select "Settings". Click the red arrows until you see "graphics settings".
Set "quality" to 1 and test the game. If you want increase it as long as it runs well.
dxdiag
Windows XP: Go to your start menu and click on run. Type in "dxdiag" and hit enter
Windows Vista / 7: Press the windows key on your keyboard
or click on the start menu. Type in "dxdiag" and hit enter.
Now click on the button that says "save all information".
It will prompt you to save a file. Save it where you can find it.
Then
zip the file and attach it to a message.