Hiya Ping, and welcome to NeoSmart Technologies!!
Unless I'm very mistaken, this is the error that occurs when you *finish* setup and select to run the installed EXE.
It's a known error, please just launch TweakUI x64 from the start menu...
Hope this helps, and if you need anything else or it doesn't work, please post back and we'll see what we can do!
-CG