I installed XP Home on this new computer two weeks ago. No sound was coming out of my headphones when plugged in to this computer, so I posted the problem here. Someone suggested that I go into Device Manager and look for "?" and other symbols. There was a "?" next to something that controls the volume or sound, and I did whatever the person suggested and the sound or volume worked until just now. I went into Device Manager, and there are no symbols listed for anything. When I go into "Accessories">"Entertainment">"Volume Control" I get a message saying:"There are no active mixer devices available. To install mixer devices, go to Control Panel, click Printers and Other Hardware then click Add Hardware. I clicked on some things listed in the "Installed Hardware" list, but for each I get a message saying that it is working properly. In CP under "Sound, Speech and Other Devices" I am able to get to "Master Volume" which controls the volume output. Nothing is muted there and everything is set to the maximum. From "Master Volume" under "Speaker Volume" both the left and right were at the very minimum, and when I moved them to the right the sound came on in my headphones. But now I cannot control the volume at whatever site I'm on. The volume is always at the same level.