A few weeks ago i was able to watch avi videos formats in windows media player 11 and now for some reason it dont let me... I have tried downloading codec such as Xvid and DivX but still not sucess... please help
Download and install the "K-Lite Codec Pack".. It will instal a load of codecs, as well as WM Player Classic, which seems to play a pretty large amount of files, including AVI format.
codec packs suck will screw up your computer at some point espicially if you try to do any type of video editing. Now what you should do is install this http://www.headbands.com/gspot/ or this http://mediainfo.sourceforge.net/en and open the avi file with either of those programs. I like mediainfo cause it will give you a link to the codecs needed to play a file. If you open the avi in gspot and it says you have the codecs installed,there is probably codec conflit somewhere.
Another option would be to install VLC Media Player...which basically plays any kind of video file. Plus, the program itself is tiny. http://www.videolan.org/vlc/