I installed the game when I had Windows 7 and it ran smoothly, after upgrading to Windows 10 though I've been getting framerate drops randomly down to single digits. Nothing seems to set it off, I can be doing anything even just walking around with nothing going on and it'll drop. Currently i've tried running the game in compatibiity mode XP (Service Pack 2 and 3). Vista (pack 2), turning off compatibility. Running as admin, turning off reflective water, I have threaed optimisation off in the Nvidia control panel, i've tried running the game in both single GPU mode and SLI, changed power mode from adaptive to maximum. I've tried the tweaks on PCGamingWiki like changing the CPU affinity to =1 etc but nothing so farhas worked. I was hoping someone might know a fix for this.

My system is Windows 10 Pro, 16GB RAM, GTX 690, i7-3930K at 3.20GHz. The game is installed on a 2TB HDD ST2000DM001-1CH164 and the game is installed to C:\GOG Games\Neverwinter Nights 2 Complete.

Maybe a dumb question, but have you downloaded the Windows 10 compatible drivers for your graphics card after the upgrade?

I didn't know there was one, i'll go get it and report back.
Edit: Errr, tomorrow. I just realised it's now 4am here...

http://www.nvidia.com/Download/index.aspx?lang=en-us

Just in case you don't know where to look.. ;-)

I done goofed the first time, I downloaded the Windows 7 driver version then spent 10 minutes wondering why it wasn;t installing...because I needed the Windows 10 version. I'll have to get used to that. Derp.

Anyway now that it's installed I tried the game it and it doesn't seem to have fixed the issue. I'm still gettting random slowdowns.

Edit: I take it back, it's helped a bit. The random drops don't last as long or as frequent but they're still there compared to when I used to have none at all =/

Maybe then it's sound related? Try this; Go to the Sound Options and select "Miles 2D Positional Audio". Also, try lowering the shadows to low and see if that helps.

If nothing of the above works, maybe it's a good time to contact support.

Looking at my settings the sound was already set to that, different options did seem to affect performance though but non fixed the slowdown. Turned shadows and dynamic lighting off too, still no good.

To support I go, but thanks for your help :)

Alright, just don't forget to post the solution here, in case more Win10 users experience the same problem. Cheers!

have you tried the "Neverwinter Nights (Safe Mode)" shortcut?

or windowed mode?
http://nwn.wikia.com/wiki/Window_mode

Yeah i've tried both and neither have an impact I still get the random performance drops.

Well I don't want to jinx it but I may have found a solution. I changed Threaded Optimisation back to Auto and then changed CPU Affinity=0 to =-2 in the nwnplayer config file. Played for 30 minutes and didn't get slowdown, i'm going to play it for a few hours more before I stamp it as solved though. Fingers crossed.

Edit: Nope.

I too am suffering this problem. Random freezes and no response when clicking on enemies in battle. NWN2 suffers exactly the same issues under Win 10.

And yes all my drivers have been updated..