I downloaded(?) 7zip free. When I right click on the 5.9.3 rar, I am not offered the choice of extracting the files. If I open the 7zip file, I get to download the same thing again. Is there a way to extract the 5.9.3 rar?
WinRAR. It's what we use to pack the modpack, so it's the best choice to unpack it. The forty day free trial is actually a permanent free trial.
I believe the term is "nagware", because after the 40 days are up, it pops up the "buy me" dialogue after a few seconds.