Often a time, running a relatively older program on Windows, let it be games or an interactive software or some encyclopaedia, etc. needs a certain type of codec to work properly. Most of the codecs are built in. However in certain cases, older codecs like MPEG2, H.261 (probably), QuickTime, etc needs specific configurations.

In general cases previously, I would just slap K Lite Codec Pack over Windows as I had little to no idea how these worked. However as time passed such codecs often replaced the official Windows equivalent of the codec and cause compatibility issues with certain software. A unfamiliar video player, for example, doesn't work well with the libmpeg codec for decoding H262 but works well with its own included codec

I am looking for ways to manually be able to install any specific codec required by an app, manually tweak the registry to use the codec, basically wanting transparency to changes I make on the system so that I have the highest control to revert it back.