Go to Start> Right Click Computer>Manage>Device manager>Sound, Video and Game Controllers. Right click on any sound devices and click uninstall, Restart the computer. Once rebooted go to Start> Right Click Computer>Manage>Device manager>Sound, Video and Game Controllers, Right click on any sound devices and click update then restart. and it should work. if that doesn't Go Start>All Programs> Windows Updates, Check for updates and click on Optional Updates and see if a update is there for the Sound card.