“.rmvb” of the REG file to the format we want, and then save to registry to finish format registration. Isn’t it quite simple? We even find out in the test that when media center is searching movie media, it only replies on file extension to recognize, namely, if you don’t want registry operation, directly change the extension of the rmvb file as the format media center supports (such as wmv, mpg etc.), file could also be recognized by media center, of curse if there are a lot of files, this mthod seems kind of troublesome.