Your memory is correct! They released GTA1 (all expansions) and GTA2 as free “Rockstar Classics” in 2003 and 2004 respectively: https://web.archive.org/web/20130116055920/https://www.rocks...

One can get those versions here: https://archive.org/details/rockstar-classics_202107

They're great on XP-era machines! I have both installed on my HITACHI FLORA 270HX

Those were GTA3 versions. The linked version is for the original GTA with the classical top view perspective.