If you find Windows Media Center freezes then check or, do the followings:-
1] If you have installed any third party codec then uninstall it.It may be incompatible.
2] Make sure you are using the latest audio and video drivers.If not,visit the websites of the concerned manufacturers to download and install the latest drivers.
3] Turn off Windows Media Center.Open %systemdrive%\programdata\microsoft\ehome and delete all files and folder in ehome folder.
4] There may be some possibilities system file corruption.To fix it go to start->type cmd->right click on it->click Run as administrator. Click Yes if UAC prompts. Type the following command and press enter: