One of the biggest irritations of mine pertaining to Microsoft Windows is
when i try to play a multimedia file, such as a .mov, or mp4, divx, xvid,
avi file and Windows Media Player will not play it. Occasionally, Media
Player will attempt to locate the proper codec, and download/install it,
however this is hit or miss, unlike Ubuntu Linux.
I found that installing "Media Player Codec Pack" to be the best solution:
http://download.cnet.com/Media-Player-Codec-Pack/3000-13632_4-10749065.html
Like normal, download, install, and avoid installing the unnecessary
toolbars.
Your welcome.