With Windows XP 64bit and on up to 7 you can easily boot Windows on a native EFI system with out a special bootloader.

For a example:
Shell> Fs0: <-- this is your optical drive
fs0:> \EFI\BOOT\BOOTX64.EFI

For the Itanium-based computers, use the following command:
Fs0:\EFI\BOOT\BOOTIA64.EFI

From an elevated command prompt, run sysprep to prepare the Windows image for imaging and deployment.
%WINDIR%\system32\sysprep\sysprep.exe /generalize /oobe /shutdown
When the Sysprep command completes, the computer shuts down.

You can access the EFI partition in windows as well. I tried this in regular XP, it worked but made the system unstable. Works quite well in XP 64bit and up.
Most of the time Windows will toss the EFI partition the Z letter. If not you can find out in diskpart or even with Disk Management.

mountvol z: /s
Then just issue the mountvol command again.