Here's a tip that sometimes solves this problem. Please note this deals with your Windows Registry, and great care should be taken to only do steps listed here.

Go to Start - Run and type REGEDIT and press Enter.

Backup your registry: Go to File - Export, at the bottom choose Export Range ALL. Choose the desktop for a location (or any other location easy to find) and type a filename of your choice, i.e. RegBackup and press Save.

Right-click on H_KEY_LOCAL_MACHINE, go to Permissions, click Advanced at the bottom of the screen, and make sure both buttons at the bottom of this screen are checked: Inherit from parent the permission... and Replace permission entries on all child objects... and hit OK.

Exit out of Regedit and reboot.

Try re-installing your driver. You may have to go into the Device Manager, find the audio device with a yellow ! and right-click and update driver and see if this solves the problem.