Hello friends, i have the desktop with the Windows 7 operating system. I have upgraded the operating system of the computer from the Windows Vista to the Windows 7 operating system. I am having issue with the playback of the MP3, WMV, AVI and many other file types on the Windows Media player. The Windows Media Player will not play regular codecs such as MP3, WMV, and AVI files. So can anyone help me out in resolving this problem.