Microsoft will not support the Extensible Firmware Interface (EFI) in its forthcoming Windows Vista operating system.
The Intel-developed EFI is designed to replace the basic input/output system (Bios) that has dominated PC platforms for more than 20 years. Both EFI and the older Bios give a machine its first instructions when it is turned on and allow the operating system to be loaded.
The advantage of EFI is that it delivers shorter boot-up times and allows hardware suppliers to bundle device drivers that are independent of the operating system.
The EFI specification defines a new model for the interface between operating systems and platform firmware. The interface consists of data tables that contain platform-related information, plus boot and runtime service calls that are available to the operating system and its loader, Intel said. Together, these provide a standard environment for booting an operating system and running pre-boot applications.
Microsoft had originally said it would support EFI on 64-bit systems, but has now back-tracked on its plans after saying there will be too few 64-bit processors on the market when Windows Vista is released towards the end of the year.
Microsoft announced its change of plan at this month's Intel Developer Forum in San Francisco earlier this month.
Microsoft has previously supported EFI in its 64-bit version of Windows XP, which is aimed mainly at PC enthusiasts.
Desktop rival Apple is already using EFI in its Intel-powered systems.