And I'm allready administrator, didnt help either.
Even if you are in administrator, you still have to
run it as administrator.
To do this, right-click your NWN shortcut, and do this:
If that doesn't work, many on the forum have said that running it in compatability mode works too.
To do this, right-click your shortcut, select properties, and go to the compatability tab. Should look like this:
Select XP service pack 2, hit okay. Then run the game in administrator mode like before.
It's also possible that the shortcut is fucked, and skipping the launcher like Peasant said might help, after doing the above.