My current merged install of GOGs EEAH and reatail EECH isn't working well. EECH doesn't see AH content so the AH-64 and MI-28 are not flyable in EECH as well as its 3 terrains are not accessible. I know it worked before with the same versions (GOG's AH and retail CH) so what gives. Both are in the same folder. Is there any registry entry that tells CH that AH is right there? Is this in some config file? Is the detection done automatically on every game start? How does that work? I already tried reinstalling both games in different locations (same folder though as this is demanded for the merge install to work) on different drives. Did I broke something by doing so, I noticed many registry entries with different install location present now. Is there anyway to fix that? Since the source code is available does anyone knows how this actually work?

Also note that I'm interested in running the vanilla versions of those sims and I know there are mods available.

Reinstalled yet again, this time to D:\Razorworks (both games) and it works now. It's weird because I tried that before on C:\Razorworks and it didn't worked, yet it worked the first time I tried it in "D:\GOG Games\Apache vs Havoc", so yeah...

Anyhoo it works fine now, but if anyone knows how the check is done please share, I'm curious.

I think it just does a check for the aphavoc exe, but I'm not entirely sure. I think they both need to be in the same root folder for it to find it, so D:\GOG Games\ rather than D:\GOG Games\Apache vs Havoc

I had a quick look at the code. It checks that the \aphavoc\aphavoc.exe exists in the same directory as \cohokum\cohokum.exe

Thanks for the info. That D:\GOG Games\Apache vs Havoc folder (default folder created by GOG installer) also had \aphavoc folder inside it beside \cohokum folder added in later so it should work which it did at first. Which was weird it didn't later...