Go to
www.divx.com and download divx lite or the lowest version of it (free and no spyware). When you are about to install it, click to just install the codecs and you should be good. If that doesn't work, make sure to do your windows updates and run windows media player and check for updates on that as well (should be included in the windows updates but just to be sure). There's also a program that I used to have that contained all the codecs you would ever possibly need in a single install file. I forget the name but I believe it was something like nemo or something to that affect (or I'm way off).