Make sure you have Windows Media Player (WMP) 11
Note: If the sharing service has been disabled on the computer WMP will not continue after this point. Continue to Step 3 "Enabling Media Sharing Service On PC" for further assistance.
Look at the "Service Status" This should be "Started"
If the setup looks like the image below sharing is disabled and the computer will not share the media on the computer.
To enable sharing set startup to "Automatic" and click "Apply" and then click "Start". [a progress bar will appear]. Click "Ok" to exit.