Every file opens with media center in windows 7

i have a friend who is having a laptop, and he got a problem where all his files get opened in media center, even when we try to open MS Words, it opens media center... and cannot shutdown the media center. it quickly opens in fraction of sec.

please help! anyone here with any idea. I think the problem started when he tried to open a file by right clicking-> open with-> media center. Now all files are opening in media center.

Here's how to fix it:
http://support.microsoft.com/kb/950505

If you open that link on the computer with the problem, you can use the "fix it for me" option. Otherwise you'll need to follow the manual instructions.