Originally Posted by koala

Go to Start > Run and type services.msc

Scroll down to Windows Audio. The description for this service says: "Manages audio devices for Windows-based programs. If this service is stopped, audio effects will not function properly. If this service is disabled, any services that explicitly depend on it wll fail to start."

It should say 'Started' for Status and 'Automatic' for Startup Type. If not, right-click Windows Audio and select Properties to change the values to Started (using the Start button) and Automatic (dropdown menu).

Go to Control Panel > System > Hardware tab > Device Manager. Click the [+] next to System Devices. If you don't see 'Plug & Play Software Device Enumerator' listed, follow the instructions below: