InstalledCodec can help you to find LOTS of mpeg codecs hanging around on my system from other software, even lots of software that I've since un-installed.

It is a small utility displays the list of all Codec drivers and DirectShow filters currently installed on your system. For each component the following information is displayed: Display Name, Type, Disabled Status, Installed/Modified Time, Description, Company Name, and Filename. It allows you to easily disable or enable any Codec/DirectShow component or export the list into text/xml/html file.

For each component the following information is displayed: Display Name, Type, Disabled Status, Installed/Modified Time, Description, Company Name, Filename, and more...
It allows you to easily disable or enable any Codec/DirectShow component or export the list into text/xml/html file.

The license of this software is Freeware, you can free download and free use this codec pack software.