I've been using RegShot for quite a while, but it hasn't been updated in quite a while.
I was looking for alternatives online, but the only program I found was called InCtrlX, which, apparently could log the changes done specifically by the installer. The program is no longer available, but I'm sure there has to be another alternative.
The program should, preferably be Free, but, most importantly it should be a dedicated program for logging/repacking installers. I've already found a couple of unrelated tools, which had functionality, that could be useful in this case, but I'm looking for a dedicated solution.