Run windows 7 on mine - mostly had to get used to if for work, as everything went that way. New laptop came with 8 on it, and that lasted about half an hour before it got dumped and rolled back to 7... Still have an XP laptop that I use for some diagnostics work though as it plays nicer..
That aside... audio wiring.
Subwoofer... wires at the head unit are Orange & Orange/Black. It's a line out level signal from the factory head unit to an amplifier in the subwoofer. If you have the premium/DSP system then the signal goes into the DSP amp first as it controls the level ultimately sent to the subwoofer amplifier. The subwoofer amplifier will power up with the other amps/DSP amp when 12V is on the Grey/Black wire (connected to the remote on wire on the head unit).
Steering wheel controls... Not a straight plug and play on most head units. You need an adapter unit that reads the voltage drop on the wire when one of the buttons is pressed (it's a resistor ladder type system) and then covnert that to the protocol for your aftermarket head unit. In my RR when I had my JVC head unit installed, I ended up buying a PAC SWI-RC unit from the USA as it was programmable, and the supposedly 'plug and play' unit from Nexxia/Autoleads didn't work, and they wouldn't give me any support on trying to make it work.
If you post a picture up of the back of your head unit, I can tell you what system you have and what each of the wires does. If it's the premium system, then I have a spreadsheet of all the wiring which I wrote when I first bought my RR and was working on the stereo system.