If this does fix the problem for you, skip to the 'Why does the game go in slow motion?' part of this post for a bit more of an understanding. This has fixed the issue for a lot of people. The first thing you should try is settings the frame rate to 30FPS. Update: A much neater, more official guide that you should look at first can be found here, unless you came here FROM that guide, in which case, scroll down to the 'Switchable Graphics' section to find the information you came for.

The rest of this post is dedicated to slow motion issues. If this does not solve your black screen/crashing issues, then I'm sorry to say, I'm afraid I cannot help you. In your library, right click Resident Evil 4, then click properties, then go to the 'Local Files' tab and click 'Verify integrity of game cache.' Although, if your issue is something such as crashing on startup or a black screen, try verifying the game cache. Note: Those looking for a fix for anything other than slow motion gameplay should look elsewhere.