TLDR
Pinned topics is extremely outdated and some info is wrong (music already there for GOG's Q2, only Q1 come with music as disc-image, no for KMK mods, no need in 3.24).
For further workarounds info and download links look here (keep in mind it is open Wiki, no 100% accurate):
[url=http://www.pcgamingwiki.com/wiki/Series:Quake]http://www.pcgamingwiki.com/wiki/Series:Quake[/url]
http://www.pcgamingwiki.com/wiki/Troubleshooting_guide YamagiQuake2 + maybe optional texture pack's
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First, there no need any of this. If game did not started for you - it something on your system prevent it from start. Reinstall to X:\Games\Quake-2\
turn off Windows DEP, 3rd party antivirusses. Close all programs (including all from sys.tray).
Set keep aspect ratio in video driver and turn of any V\G-sync's in driver (set 'by application'), make sure in video driver and in Widnows power mdoe set to maximum\no power saving.
For GOGGalaxy build do verify games files - twice in a row.
Start game from gog link, not by quake2.exe
Exit the game and tweak autoexec.cfg file for fixing a lot of general opengl render issues and some else tweaks (fps limit, shadows).
Or you can alretnatively to tweaked autoexec (editing fps limit and shadows is still manually) fix opengl render by installing sourceport-mod.
0. First step - precompiled 3.21.
1. 3.21 pre-compiled patch + Facelift mod (it is also source port) (it is come as dll + quake2.exe file,or actually additional patch for quake2.exe that you should run from same folder as quake2.exe).
2. same as above + additionally DirectQ2 + 3.21 dll from same author.
DirectQ2 is single exe file, no even dlls replaced. Not sure if it can be combined with every else sourceports, with some simple light ones.
You need find 1.0 and then 1.1, author did not include in same archive his 3.21 dll for 1.1 version and his sites are dead, on his github it is another implementation of DirectQ\2 - for d3d11 render.
Both sourceport-mod's - Facelift mod and DirectQ2 - allow to play in widescreen. You dont need music tweaking - they both work with GOG music as is. Music work.
For DirectQ2.exe you need copy Q2Launcher.ini file, edit it quake2exe-directq2exe, rename it to DirectQ2Launcher.ini, copy GOG link and change last promt in link from -Q2Launcher.ini to DirectQ2Laucnher.ini. When you want opengl render start it by old GOG link with Facelift mod, when you want D3D9 render - start it from new DirectQ2 link. GOG Laucnher exe keep untouched.
3. For further QoL improvements - already mentioned here - YamagiQuake2 sourceport mod. Probably, it can be installed above already modded game, or maybe not - i didnt test it. Reinstall clean offline GOG version (setup_quake2_quad_damage_2.0.0.3), and exctract YamagiQ2 to it. Start it from yamagiq2.exe.
Music foldr probably need to moved to baseq2. Or probably not. Yamagi maybe fix that long ago, and GOG version is 100% supported.
4. For changing graphics - Quake2XP or Quake2RTX. Start from them new exes, install similar to YamagiQ2.
You can skip steps to 3 or 4.
