So I have downloaded, extracted and put the ACOK 1.0 into the modules folder, but still I can't find it in the launcher.
Does anyone know a remedy?
Check if it's in the correct folder. Is it in the same folder as your other mods?
I just tried creating a folder with nothing but a module.ini copied over from Native, and it was recognised as a mod by the launcher. As such, as long as your folder is in the correct place, there's no reason the launcher shouldn't recognise it.
The path is
C:\Program Files (x86)\Steam\steamapps\common\MountBlade Warband\Modules\ACOK 1.0
and inside that last folder are the module.ini and all other files. Obviously, adjust the initial path accordingly if your installation location is different, but everything after the Warband folder should be the same.
Check that your path isn't something like
C:\Program Files (x86)\Steam\steamapps\common\MountBlade Warband\Modules\ACOK\ACOK 1.0
or anything along those lines, for example.