There are several points of view on this issue....
Currently my "dedicated" Hauptwerk computer is a dual core Intel with an Asus motherboard, 16 Gb memory, 120 Gb SSD and a 500 Gb storage drive. It runs Win7/64 bit Pro with SP1. It has been on the internet once in it's life. Just long enough to activate Windows. All networking and on board audio is disabled, no other software installed except that which is needed by the organ. All services and extras are disabled if not directly needed. That being said... I don't spend time troubleshooting problems with the computer. Hauptwerk runs fine, I have had virtually no glitches since starting with this system. The Hauptwerk 4.2 upgrade went as one has come to expect, flawlessly........
Just another take on the subject... of course the whole mess might go up in smoke tomorrow, but for now I have no intention of allowing Microsoft to put tons of unneeded crap on my system.