In oreder to work on windows codecs needs to be registered into the system first.

You can register codecs by using Microsoft register server regsvr32 that comes with Windows OS.

You may want to register a codec manually using regsvr32 if codec have not installer or in case when installer failed to register 32 bit codec on Windows x64.

In case you want to update codec that is already registered on the system with most current one, you can just overwrite codec file, but you need to do it when codec is not in use (close all programs that may use the codec you want to update).

To register 32bit codec on Windows x64 you need to execute regsvr32.exe by specifying full path to it. Registering 32bit codec on Windows x64 is doing by calling regsvr32.exe from sysWOW64 folder, but not from system32 folder!

For example to register codec file named videocodec.ax located in folder Program Files\Media Codecs on drive C you need to open Command Prompt or Run dialog and to type the following comand:

C:\Windows\sysWOW64\regsvr32.exe "C:\Program Files\Media Codecs\videocodec.ax"

Please note that text after regsvr32.exe is quoted. This is required because text contains white spaces. If path have not white spaces, quotes are not mandatory.