I was frustrated out of my mind with my Dell, probably because of what JR said about Dell having substandard parts. I was ready to ditch it, and was seriously pricing Mac, like you, out of sheer frustration.
I got a BFG GTX260 OC edition, and have not had any problems since, except once I got a bad install of Vista SP2. I had to roll back the machine, and re-installed, and then everything was fine. But you cannot really blame that on MS.
My other problem was that I accepted the MS driver for the BFG GTX260. That was a mistake, and I won’t do it again. Now I carefully screen out the MS version of video card drivers. I have not had any more problems.
I am sorry to hear you are having a bad experience. Like some have said, it is probably not because of MS: it is probably because of your consumer-grade parts. I wrote Sony and suggested they post an ‘approved parts’ list (kind of like Avid), but they did not do it (probably because it is just too hard to keep up on it). But when I build a new machine some day, I will probably do as John recommends and build a home-made box with top-notch parts.
I wish it was working for you. If you are seriously considering dropping the money for Mac, you might also seriously consider an HP Z800, or something. It is too rich for my blood, but I guess some people really have great success with them.
I wish you the best, no matter what your platform.