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Microsoft simply does not currently support UEFI, even in Vista, so hardware manufacturers are also reluctant to support it. Initially I was told it would be two to three years before general UEFI adoption. However, after a quick chat to someone in the know, the AMI rep (that spoke English) confirmed to me that Microsoft will be offering UEFI support as soon as Q4 this year through an OS update. AMI itself was completely ready to ship on mass, and are just waiting for the market to catch up.