When surfing the internet and download a specific file, especially the .3 gp file was in the file was inserted by a particular program that changes the opening program exe format on a computer with windows media player. If that happens do not panic because the cure is available, please download the following files:
http://www.4shared.com/file/255921851/1db59f3/exefixwindows7.html
Then Extract and click on your computer, and will automatically change the existing registry settings your computer, to see the results please restart your computer.