
you should also verify integrity of game files on steam, in case of any missing or corrupt files are leading to this problem. Program Files (x86) / Steam / steamapps / common / Call of Duty World at War lastly, click "apply" and then "OK" to complete the process. there go to "compatibility" tab on little window and select "Windows XP Service Pack 3" from the list. to do that go to where WaW is installed on disk and find "CoDWaWmp.exe" file.

you can run multiplayer part of the game on Win XP SP3 compatibility mode.

I still can't guarantee any success, because for old PC games like WaW, it's usually not too easy to detect the reason behind the problems. I don't know what exactly causes this issue, but you might try several potential solutions mentioned below. It's really strange, as campaign/zombies is often the more troublesome part which gives crashes at launch.
