My Arduino UNO R2 works great in Windows 8 Pro.
Thanks a lot, for all !
My steps:
0)Install IDE and change driver port as shows: http://arduino.cc/en/Guide/UnoDriversWindowsXP
1)Restart Win8 then run pressing F8 for "Disable Driver Signature " like here Missing digital signature for driver on Windows 8 - #14 by LouisDavis - IDE 1.x - Arduino Forum
2)Log out from any user account (even if administrator privvileges etc.) and log as main Administrator account (create new or Turn on from Win 8 Control Panel if Admin disabled)
2)Install this: Arduino Forum
3)Connect to other USB port.
4)Run as admin then rejoyce
I,m using simple USB white cable from printer.
Official Arduino 1.0.2 IDE start now properly.
My first day with Arduino 8)