On Thursday, at the Intel Developer Forum in San Fransisco, Microsoft development manager Andrew Ritz revealed that Windows Vista, the successor to the aging Windows XP expected to be released later this year, will not support EFI booting. Ritz admitted that EFI support will not be seen until Longhorn Server is released in early 2007, and on top of that it will never support a 32-bit processor.

Extensible Firmware Interface (EFI) is the modern and flexible successor to the 20-year-old PC BIOS. It is responsible for initialising hardware in the PC, and importantly, device drivers are stored in the EFI flash memory rather than being loaded by the operating system.

This is terrible news for Intel Mac users who have been hoping that they could dual-boot Windows and Mac OS X on their new Macs: not only are their processors not 64-bit (and thus will never be supported by Windows EFI booting) but Windows Vista won't boot on EFI anyway.

"A combination of factors changed our plans. The big one, in my opinion was platform availability. With this huge move to 64-bit based platforms and for us to support it, we needed to see a large heterogeneous sample of 64 bit implementations out there for us to feel comfortable in supporting it." said Ritz.

That sucks for mac people.