Attempted to install and run the original Baldur's Gate (purchased from here, of course) and ran into an error where upon launch I would get an error saying that I had insufficient drive space. Kind of odd, since that particular drive had almost 4 TB free on it.

Moved installation off of that system, to my old backup system (Old Dell Optiflex 9020 with a 2TB HDD as it's data drive) and the game installed and launched flawlessly.

TL:DR Original Baldur's Gate not a big fan of logical drives, or big 4 TB logical drives, anyway.

That's because 4TB was an unfathomably large drive size back in 1998. 4TB is too large of a number for the variable the game uses to calculate free space, so it overflows / wraps around and makes the game think there's only a tiny little bit of free space left.

PCGamingWiki lists a fix (Windows compatibility profile) for all the Infinity Engine games:

https://www.pcgamingwiki.com/wiki/Baldur%27s_Gate#.22Not_enough_free_disk_space.22_error_followed_by_shut_down_on_large_capacity_partitions

OrIgInAL IM sO OLd scHOOLL yEaH

People who enjoy the originals are a minority anyway and there's virtually no support for them, so I don't see the point of your constant venom towards these versions. You went through several threads just to make poor quality and low effort comments that bring nothing useful to the discussions, just to probably stroke your ego and to show how you believe that the EEs are superior.

This thread is about the original game: you don't play them and don't like them? Move on and don't waste your prescious time on this.

As for this particular error, I know that it shows up in the CD version of the game and you should be able to just ignore it and the game would install just fine.