Thursday, September 30, 2010

Boot WinPE 3.0 USB key on EFI system

Yesterday I was trying to build a bootable USB Key with WinPE 3.0 (from Win7/2008 R2 AIK) to use on my new IBM x3550 M3. I was unable to boot the computer with the key. Strangely the key works fine on another computer.

I was building my boot image (boot.wim) for x86 (32bit) OS. This morning it hits me, why not try to build an x64 image (amd64) ? and it worked !

Here’s my understanding of the problem (and I could be wrong) :

My IBM x3550 M3 is an EFI (Extensible Firmware Interface) system, you know the replacement of the old BIOS. It looks to me that booting an EFI system with a x86 WinPE is not supported because the bootmgr.efi file is missing. When you build an x64 (amd64) WinPE the file (bootmgr.efi) is present and everything works fine on my server.