Game works fine in Windows 10 - follow the installation instructions for Windows 8 in the self-help thread. If installing the GOG version of diamond make sure you install it to C:/NeverwinterNights/NWN - NOT the default location the GOG installer wants to use. After its installed, run the 1,69 Critical Rebuild, then set the EXE files to use Windows XP Service Pack 3 mode.
Depending on your system's configuration, you'll get different mileage out of the game. For example, some people have to use compatibility mode while others don't, some have to use Run as Admin while others don't, etc. Its more trial and error than anything else. AND if it's some Microsoft compatibility wizard telling you the game cannot run in Windows 10, well everyone knows Microsoft don't know crap...
There is more information on mine and others' personal experiences with NWN and Windows 10 HERE.