This ASF / MP42 Microsoft High-Speed MPEG-4 V1/2/3 Codec has not been developed anymore since 2004 and it is compatible with following operating systems: Windows 95, Windows 98, Windows ME and Windows XP.
In order to install this codec to your computer, you need to extract files from the MicrosoftMPEG4.zip archive. Right-click on the MPG4VKI.INF file and select Install.
You will probably be prompted that the software you want to install has not passed Windows Logo Testing, but you should click on the “Continue Anyway” button.
Then check the installed codec. See
Checking Installed VIDEO and AUDIO Codecs In Windows XP guide.
After the Microsoft MPEG-4 V1/2/3 VKI Codec is installed, you can play ASF and AVI files in Windows Media Player or in most DivX players.
http://www.free-codecs.com/