Hi,
Call of Duty: World at War is compatible with Windows 7 32 bit and 64 bit Operating System.
http://www.microsoft.com/windows/compatibility/windows-7/en-us/Search.aspx?l=en-us&type=Software&s=Call%20of%20Duty%3a%20World%20at%20War&os=32-bit
Follow the suggestions and see if it helps.
Method 1
Check if the issue exists in a clean boot state.
How to troubleshoot a problem by performing a clean boot in Windows Vista or in Windows 7
http://support.microsoft.com/kb/929135
Note : After troubleshooting follow Step 7: Reset the computer to start as usual
Method 2
Uninstall and reinstall the game and then check.
Uninstall or change a program
http://windows.microsoft.com/en-us/windows7/Uninstall-or-change-a-program
Note : Make sure you’ve the installation disc before you uninstall the game to install it back.
You may also contact the game manufacturer for better assistance on this issue.
Also see:
32-bit and 64-bit Windows: frequently asked questions
http://windows.microsoft.com/en-US/windows7/32-bit-and-64-bit-Windows-frequently-asked-questions
How to determine whether a computer is running a 32-bit version or 64-bit version of the Windows operating system
http://support.microsoft.com/kb/827218
Make older programs run in this version of Windows
http://windows.microsoft.com/en-US/windows7/Make-older-programs-run-in-this-version-of-Windows