Where does it save the progress in mk4?
I only need to beat the game with the 6 right fighters. And wanted to backup my progress but don't know where the file is?
How i know i only have six fighters, with kombat theater it shows which movies you still haven't unlocked in practice.

The registry?
That is of no use to me for someone who usually just transfers a save game file from somewhere.
But i still marked you as solved. At least i know how it works now.

You kind of can do that :)

Open regedit.exe, go to that branch, right click on it and press "Export". You can save its content in a ".reg" file, which in practical terms is a plain text file, which you can open with any text editor, i.e. Notepad.

Then, you can move that .reg file around between computers, and when you want to restore the save, just double-click it.

Just one warning: be sure to be exporting the right branch. Some searches of "gt interactive" just return the installation path of the game. It's easy to identify: its the one with a key named "config" which has a lot of data in hex form (i.e. "9f,17,b5,f7,67...").