I picked up my Win64 from somebody who couldn't use it on his machine, Couldn't get his system to work with the new technology.
Since I built a new AMD64 system, it looked like a good deal, $100 for the program.
He activated it but couldn't get the drivers for his hardware. All kinds of problems as he put it. Well, my point is that when I tried to register it, I had to call Microsoft to get a new registration 42 digit code. Imagine to my surprise after talking to a real person, the installation was finalized.
Next came the search for x64 drivers
The ASUS mobo came with its own drivers disk so that went OK, next was my ATI's turn.
The ATI website had the x64 drivers update and my dual monitors was up and running.
I found that my other hardware took a little longer to work but I Goggled my way to success, finding what I needed after downloading drivers and updates. Imagine my little struggle trying to get the right device compatibility with the new x64 system.
I've noticed faster downloads off the x64 IE and my applications seem faster. Its kinda early to start raving about this new software but given time, I will see.
I'm planning on building a x64 Linux system next month and that should be interesting also.