CPU affinity doesn't make any difference unless you are on a P4 and you somehow stuck it on a virtual core (not a real core, but a hyper-threading one).
Also CPU affinity of -2 does exactly the same thing as 0, the default value as -2 is simply a nonsense value.
If you have had a change after this, it is merely coincidence.
, DirectX, 1.69 patch, and Windows XP SP3 compatibility mode is what you need.
1.69 Patch: http://files.bioware.com/neverwinter...HotUUpdate.exe
On newer installs of Windows, you may be missing some older DirectX files: can directx 9 co-exist with directx 11 on windows 7? - Microsoft Answers Have DirectX 11 won't play games, says I need DirectX 9.0c - Microsoft Answers
That and directly install latest graphics card drivers from NVidia/AMD, I have had odd results installing graphics driver
updates from "Windows Update".
Properties-> Compatibility tab
check -> "Run this program in compatibility mode for:"
select -> Windows XP (Service Pack 3)
under Privilege Level,
check-> "Run this program as an administrator"
I have run NWN on my Win_7-64 machine through all of the original campaign (+SoU and HotU) and several third party modules, sometimes playing 6 hours straight. It is rock solid. This is my favorite game of all time. I was playing HotU again on Sunday past.