FF users may have to do this:
1- Close FF
2- go to Documents and Settings folder
3- Application Data --> Mozilla --> Firefox Folder
4- Open with notepad or other program the file pluginreg.dat.
5- Change this code:
Npdsplay dll|$
Windows Media Player Plug-in Dynamic Link Library|$
10 <-- changed from 9 to 10
0|application/asx|Media Files|*|$
1|video/x-ms-asf-plugin|Media Files|*|$
2|application/x-mplayer2|Media Files|*|$
3|video/x-ms-asf|Media Files|asf,asx,*|$
4|video/x-ms-wm|Media Files|wm,*|$
5|audio/x-ms-wma|Media Files|wma,*|$
6|audio/x-ms-wax|Media Files|wax,*|$
7|video/x-ms-wmv|Media Files|wmv,*|$
8|video/x-ms-wvx|Media Files|wvx,*|$
9|video/x-msvideo|Media Files|avi,*|$ <-- Added
Now the files will be displayed using Windows Media Player.
NOTE1: Be sure when u edit the pluginreg.dat FF is closed or it wont work.
NOTE2: If u dont find the "Application Data --> Mozilla --> Firefox Folder" in ur Documents and Settings folder, be sure u do this:
1. On the Tools menu in Windows Explorer, click Folder Options.
2. Click the View tab.
3. Under Hidden files and folders, click Show hidden files and folders.
After editing the file u can again uncheck the Show Hidden Files option.