With the issue you are experiencing spreading to your other games, leads me to believe it is a system problem. It's possible that a Microsoft update was automatically applied and is causing your issue.

Did you install any (and yes, I mean ANY) new software or hardware between the time the game was working to when it wasn't? The way to find out: Start Button -> Control Panel -> Programs and Features. Sort the list by "Installed On". Anything that was installed on the day you installed WaW to when you first started experiencing problems must, at this point, be considered suspect. You can also click on "View installed updates" on the left to see what MS Updates have been installed.

Some other thoughts I had:

Perhaps DirectX has become corrupted on your system. If an update didn't fix the problem, perhaps DirectX needs to be un/re-installed. I found a program that allows you to manipulate your DX install called DirectX Happy Uninstall. I have never used this program, so I can't offer much help. But, please be aware, that fiddling around with system components is always a risky affair and extreme caution should be taken while using the uninstaller. If the uninstall goes fine, simply visit Microsoft's website and download the latest version.

Have you tried rolling back your video card driver? I have had success doing this for other games.

What type of soundcard do you have? If it is a Realtek HD audio chipset on your motherboard, use the Realtek drivers instead of the driver supplied by your motherboard manufacturer. Note - I do not use my onboard sound, so I cannot confirm if the driver link above is for what you need.

**EDIT**

You might also try rolling back your system to a point before the install of WaW using System Restore. I'm not sure where it is in the Control Panel, so click your Start Button, then type "system restore" in the search box and it should come up.