Thanks Tim for the response. I understand that Microsoft began supporting UEFI 2.x with the release of Vista x64 SP1 and that I can run Vista x64 SP1 on the T400. My question is does the current BIOS for the T400 support the option to boot UEFI? There are a number of systems currently on the market that are capable of running Vista x64 SP1 and with chipsets that support UEFI, BUT... the current BIOS images from those vendors DO NOT support UEFI. For example, MSI has a motherboard available now that has the hardware support for UEFI (the MSI P45 Platinum), but they haven't finished the BIOS yet that supports UEFI, ergo my question about the state of Lenovo T400 BIOS. Thanks for your reply.