(works on XP x86/x64 host)
01] prepare usb disk for win7 boot:
create new partition, set partition active
copy usbbootfix.bat to usb drive
02] create new vhd file (dynamic expandable, size 16GB)
03] install win7 rtm in virtual pc or virtual box
(backup the vhd file, if you want to repeat step 4]-6]
04] create new virtual box virtual machine
and boot this VM from vhd created in 2] and attached usb disk from step 1]
inside VM (run the tasks as administrator) :
a] assign drive letter Z: to usb disk from step 1]
b] Copy Boot folder and bootmgr from boot partition > Z:
c] unassign drive letter from boot partition (system reserved partition)
d] run cmd as administrator and type:
bootsect.exe /nt60 Z: /mbr bcdedit /store Z:\Boot\BCD /copy {cureent} /d "boot from VHD"find new GUID for copied entry
(type bcdedit /store Z:\Boot\BCD to list all boot entries.)
bcdedit /store Z:\Boot\BCD /set {new GUID} device vhd=[Z:]\win7.vhd bcdedit /store Z:\Boot\BCD /set {new GUID} osdevice vhd=[Z:]\win7.vhd bcdedit /store Z:\Boot\BCD /set {new GUID} detecthal on Z:\usbbootfix.bat05] shutdown VM
06] copy vhd file to usb disk from step 1]