I would say 90% of programs will let you choose where to install them. It's only steam games where you have to tell steam in advance that "hey I may want to install a game on another drive than my C: drive, so setup a steam library there."
120gbs will go fast if you put any games on there, but typically programs aren't anywhere near as large as games are, because they don't have things like uncompressed audio files (that's why game file sizes have increased so much in recent years. It's a terrible anti-piracy measure.)