I was wondering if anyone knew of any reason why a DVD drive would stop reading game discs, but continue to read DVD movies. My problem began earlier today when I installed Call of Duty 4: Modern Warfare. It installed normally and I was able to play right away with no problems. Now when I try to come back to play more of the single player part of the game, I just get an error message that says "Cannot locate the DVD-Rom. Please insert the correct DVD-Rom, select OK and restart application", despite the fact that the disc is in fact in the drive. The disc is clean and unscratched. I tested two other games (neither of which have ever given me this type of problem before today) and I also get messages stating that there is no DVD in the drive, but DVD movies continue to play. Although, recently, DVD movies have been occasionally freezing after a while. I've been searching for hours trying to come up with some sort of way to get my games running, but despite finding quite a few others complaining about this same problem (most with with the very same game or those in the series) I've been able to find no solutions or much insight into my problem. I've tried firmware updates for my DVD drive, but have been unsuccessful in even installing one. I was hoping that someone might have some knowledge of this type of issue, and whether it indicates a hardware failure (in which case I would just have to replace the drive?) or something else. Thanks a lot to anyone who can offer me any kind of assistance.

Try completely restarting your computer and then launching the game by putting in the DVD rather than clicking a shortcut then inserting the DVD. In my experience if a game isn't completely exited out of there can be problems starting it up again.