Thanks, tried that but it doesn't work. (see also Closed Captions - Windows 7 Forums). The does work for subtitles, but not for CCs.In WMC:
1. On the start screen, scroll to Tasks, click settings, click TV or DVD, and then click Closed Captioning. In some regions, you may need to select Subtitles instead of Closed Captioning.
2. Under Caption Display, click either On, Off, or On when muted.
3. After you have completed your changes, click Save to return to the settings screen.