Alright, I´ve made my peace with not ever getting my copy of MDK2 working on my retro machine, so be it. However, I did found a way to fix the notorious "Could not load OpenGL sub system" error message for id Tech 3 games.
- I re-installed the games, didn´t work
- I re-installed DirectX 8, didn´t work
- I re-installed the GPU drivers, didn´t work
- I re-installed the core files from Unofficial Service Pack 3.64, WORKED!

So if anyone else has been struggling with the same problem, at least now you how fix that frustrating error caused by MDK 2. Thanks everyone!

I have never seen MDK2 cause an issue like this on any of my setups throughout the years and I have played and benchmarked this particular game countless times on way too many configurations. It could very well be the unofficial Service Pack that has caused you headaches.

Garrett W wrote on 2020-05-15, 10:19:

I have never seen MDK2 cause an issue like this on any of my setups throughout the years and I have played and benchmarked this particular game countless times on way too many configurations. It could very well be the unofficial Service Pack that has caused you headaches.

That´s very possible. I´ll test it some day without USP and let you guys know if it did the trick.

Consdiering there have been systems like the OP able to play MDK2 in 2000-2001 long before USP was even concieved...

Intrigued by our Finnish friends original problem. I've been trying to get MDK2 to run on my 98SE machine, on and off, for months without success. Every time I swapped bits out, which is pretty regularly (hee hee), I'd have another go.

Just for a laugh, I tried it tonight on my XP gamer. It bloody well worked, straight away with no complaints and everything maxed out!

Just thought I'd mention it.... 😁

texterted wrote on 2020-09-30, 00:42:

Intrigued by our Finnish friends original problem. I've been trying to get MDK2 to run on my 98SE machine, on and off, for months without success. Every time I swapped bits out, which is pretty regularly (hee hee), I'd have another go.

Just for a laugh, I tried it tonight on my XP gamer. It bloody well worked, straight away with no complaints and everything maxed out!

Just thought I'd mention it.... 😁

Does your Win98 rig have the unofficial service pack? If so, it may just very well cause this issue. I´m wondering what it is in USP that upsets MDK 2 and why hasn´t this issue occured with any other game?

I can't remember if this build has it installed, could well be. It's due a reinstall anyway, so I'll try the game again when I do it.

I have similar issue with MDK2 demo - Win98SE and Geforce 4200 TI + 43.51 driver, with Windows 2000 + XP its working fine, but same binary is not working with Win98 - im getting generic OpenGL driver slideshow (1-2 FPS and very slow, maybe infinite loading).. all other OpenGL games like Quake1,Quake2,Quake3, Half Life demo, Vampire Masquerade are running fine.