I have seen a number of posts relating to missing sound but none that seem to relate directly to the problem I am having. My son just got a new HP desktop computer running W7. Everything appears to work except the sound. The speaker icon in the task bar has a red symbol next to it and if you highlight it you get a message that says there is no speaker attached to the system. I have tried a couple of different speakers that I know work but the system does not seem to recognize that there is any speaker attached. Any idea of how to trouble-shoot this would be appreciated.