Do you have problems running a Steam game like Call of Duty Black Ops? Maybe all you need to is to verify your Steam game cache integrity files.
1. Step Open Steam
2. Step Click on your Games library
3. Step Now right-click on the game name e.g. Call of Duty Black Ops and click on Properties. Keep in mind this will only work for Steam games, not for shortcuts to games.
4. Step Next, go to the tab Local files
5. Step Below click on Verify integrity of game cache
6. Step Wait until Steam validated the game cache integrity: