I think their requirements are for if you want to run Aero though. There are a lot of "special effects" (no better way to word it) that Vista uses that should be able to be disabled.
AMD Athlon 64 3200+ Venice Core, MSI K8N Neo-4, 2x 512 Corsair Dual Channel, Nvidia Geforce fx 6600 256MB, 160GB HardDrive
Windows Vista Business Edition
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