Ok it would help if I could get the complete error message you get. But for now I'm going to assume you have win 7 and the game installed and all the patches ?? Thet are 6 patches 1.0 to 1.1, 1.1 to 1.2, 1.2 to 1.4, 1.4 to 1.5, 1.5 to 1.6, 1.6 to 1.7. If that is the case I would delete any desktop icons you have then open up windows explorer and go to. local disk/ progam files (x86) /Call of Duty World at War. In that file scroll down til you see the CoDWaWmp.exe icon and right click on it. I do want you to run the game as an administrator but more important I'd like you to run the trouble shoot compatibility program. Then the troubleshoot program then check off the first box so the game will run in compatibility mode. Hope that works for you good luck.