Right click > Properties > Compatibility > Run this program in compatibility mode for > Windows XP SP3
Tried it. It works and eliminates all the fps lag and stuttering.
Go to NWZLauncher under
Local Disc > Program Files > Steam > steamapps > common > AVA > NWZLauncher
Right Click on it
Click on the Compatibility Tab
Tick "Run this Program in Compatibility Mode"
Put it to Windows XP Service Pack 3.
Try it & rep DontCaeria. He deserves all the credit. c: