When installing NWN2 today, I discovered, it’s best to do so from my GOG copy. The alternative would be to use one of my DVD sources, however the GOG copy comes with the extra games and most importantly the patches downloaded. The patch server has gone and so installing from disk does not work so well, by which I mean the game cannot be patched.
Some mods are best installed before a game starts, see Zhjaeve Unveiled.
This thread at GOG, talks about W10 compatibility mode.