If you experience a low volume issue within Windows Media Center,eg. playing a movie or a video clip then try to resolve the issue by the following way:
Press Win + S Keys to open Search within Metro interface.
Type in Troubleshooting
Select Hardware and Sound
Click Playing Audio and follow on-screen instructions.
Open Windows Media Center
Scroll down to Tasks > Settings
Uncheck the box against Auto Volume.
Make sure that the audio driver is updated.If not,visit the website of the manufacturer to download and install the latest driver.