i recently completely reset my computer to factory settings and now on can only play music for a little while then it says there is no audio output device. also whe i click the volume thing at the bootm right hand corner it says there are no active mixer devices available
You need to install the driver again.
If you are usings windows, go to start - control panel - device manager select the sound,video and sound controller.
Try and install the driver from there... if the wizard cant find the driver needed. Try google the device name and install the drivers from the web.
Or if you got a backup disk that should have the drivers you need.