As many who have graduated to extremely large capacity drives may have noticed, the original "Unenhanced" versions of all the old Infinity Engine games do an internal check for free space and will fail that check if free space exceeds what that check was designed for. This is especially painful in the case of Icewind Dale II since there is no planned Enhanced Edition of it forthcoming.

I now have a set of compatibility settings implemented via batch file which will (among other small fixes) set Windows to report no more than 2GB free space to each of these games and only these games. The check does so via file name and game publisher info located in the file, which should prevent false positives such as if you launch the enhanced edition (if all you own are the Enhanced Editions of the game, disregard as this fix isn't necessary and won't affect those versions). This applies to Baldur's Gate 1 & 2, Icewind Dale 1 & 2, and Planescape: Torment.

https://mega.nz/file/ahkWjbxR#rEKQssrG_0XgL8djCrZEUieScflxmBvUzWSGfSEycy8

(This fix was originally designed by a redditor who designed it for me privately. They prefer to remain anonymous so they aren't bothered by requests to improve it down the line. It also includes a PDF listing instructions on how to create this compatibility fix for this and other games with similar checks.)

As mentioned in the Baldur's Gate forum, this isn't necessary since you can simply click "install anyway" and the games will install without issue. And, in fact, it won't happen at all for Icewind Dale II since the total install size is less than 2GB.

https://www.gog.com/forum/baldurs_gate_series/fix_for_baldurs_gate_out_of_space_error_and_all_other_infinity_engine_games/post2

This isn't for the installers, it's for the main game. It solves an issue that only comes up on partition sizes over 2TB. If you launch in those conditions, the game will report this error and not give you an option to continue anyway. It will simply crash.

Prior statements retracted and apologies offered:

https://www.gog.com/forum/baldurs_gate_series/fix_for_baldurs_gate_out_of_space_error_and_all_other_infinity_engine_games/post4

Thanks for providing a solution to this issue. :-)