A year ago, I posted this for other users having the same problem: That was using v2.7 and the extension trick made the issue disappear. Today, I installed the v3 of NOD32, and the problem is back. Tried the extensions trick, but this time it didn't solve it. I excluded both the windows media player exe and its directory, but still, no solution. It is really annoying, because it doesn't happens everytime, you basically need to keep trying to execute video files.