I just took a deep breath and bought the game. Lucky me, I can now confirm that the game works just fine on Windows XP Pro x64 Edition SP2 (NT 5.2 64-Bit kernel). I guess official support on XP and XP x64 shouldn't be a problem, it works just as fine as the last installment. :)
I am currently using Windows XP Pro x64 Edition. I'm kind of a die-hard XP user, and XP x64 gave me nice things like 64-bit address space, Storport storage driver model, and GPT data volume support for my large RAID-6 , so it's features which I all use, that's kind of the maximum I can get out of XP. ;) I even use it with quite modern hardware, i7 980X, 24GB RAM, an Intel 320 SSD with my system partition properly aligned to 1MiB (and TRIM on XP using the Intel SSD toolbox)
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