I'd like create a usb device that can start x86/x64 WinPE, but by default the system from first partition (equivalent to grub hd(0, 0)).
The dual boot can be quite easily done by adding both images to source folder and modifying bcd with bcdedit (details here).
Adding first partition boot also seems fairly simple - add a bcd entry with device/osdevice set to partition=C:. The problem is it doesn't work for computers with and without the boot manager partition (100mb by default for win7).
I noticed that when I use bcdedit to set device to partition=C: on a computer with hidden reserved boot partition, it is marked as "unknown" on the computers without that partition (and vice versa).
I could add both options but I'd like the system to boot even if the drive is connected (hence "default" will work for only one computer type).
Does anyone know if there's a possibility to solve this problem? A proper solution and any workaround (like "goto other-option if this fails") will be appreciated.
I think I reached limits of my knowledge in this subject - I've spent hours on google'ing and reading but haven't found what I'm looking for.
I'd like to achieve it without grub/grub4dos (even though it'd probably be easier this way).
EDIT 1 It seems that root (hd1,0) works for both computer types with grub4dos (so that's my backup plan). It still would be better if it was possible with standard ms bootloader.