Note that Windows 7 USB/DVD (Microsoft store) Download Tool doesn’t seem to properly prepare the USB flash drive for UEFI booting.
Requirements

4 Gb USB stick/flash drive

Windows 8 Enterprise Installation files (either their own image or from the Volume Licensing website)

Windows 8 PRO running on a Surface Pro device
Make a bootable USB flash drive using DISKPART

Run CMD.EXE as an administrator (Win-X then A), then run DISKPART with the following commands (not case-sensitive):
Command What it does
LIST DISK                 Shows all mounted disks.  Find your USB flash
SELECT DISK n          Selects the disk that future commands will use.  Replace ‘n’ with the disk # for your USB flash drive.

NOTE:  Be careful that you don’t select your hard disk!  The next command will wipe the selected drive clean.
CLEAN Erases all previous partition & volume information on the flash drive.
CREATE PARTITION PRIMARY    Partitions the flash drive as one partition for the whole drive.
SELECT PARTITION 1          Selects the new partition so future commands will operate on it.
ACTIVE                    Marks the new partition as active so the BIOS/UEFI can boot to it.
FORMAT FS=FAT32  QUICK        Formats the partition as FAT32.

(NOT NTFS!)  EXTREMELY IMPORTANT!
ASSIGN                   Assigns a drive letter to the flash drive.
EXIT                        Exits DISKPART

At this point your USB drive is formatted.  DO NOT format the drive with Windows Explorer or format.com; you will not be able to boot from it.

Copy files to the USB Drive and Prep Disk

Copy the Windows 8 Enterprise Image files to the USB drive (use XCOPY or ROBOCOPY) both of which are available in Windows 7/8.

robocopy <source directory> <usb flash drive root directory> /mir

Example:  robocopy d:\Win8Files e:\ /mir
(Change the destination to the folder that you have extracted Windows image on disk)

cd boot
bootsect /nt60 X: (X is the drive latter of your USB drive )
OPTIONAL, if you do not have USB Ethernet cable – Add the Wireless Network Card driver

Download Marvell AVASTAR 350N driver from Windows Update Catalog – http://catalog.update.microsoft.com/v7/site/home.aspx

Double Click .cab file and copy contents to a directory on the USB stick

Copy c:\windows\system32\driverstore\surfaceaccessorydevice.inf_amd64_74faf8b2bdd32b88 directory to the flash drive
Boot off USB drive – Get into UEFI setup screen

Shutdown Microsoft Surface PRO

Hold volume up and press power, keeping volume up held down

Click Secure Boot, then click disable

Boot into Windows 8 on Surface

Insert USB stick into Microsoft Surface PRO

Press Windows Key + R

Enter : shutdown.exe /r /o /f /t 00

After the system restarts – Click boot from another device

Select USB device
Install Windows 8

Go through normal Windows 8 Enterprise setup
OPTIONAL – Add the Wireless Network Card to the System

Open device manager

Right Click Marvell Wireless Device – select update driver software

Choose “Browse my computer for Software”

Browse or enter path for the directory on the USB where you put the network driver

Right click the Unknown Device – select update driver software

Choose “Browse my computer for Software”

Browse or enter path for the directory on the USB where you put the surfaceaccessorydevice driver
Finishing up

Join your wireless network and run Windows Update

Right click the last question mark device – select update driver software

Click automatically install driver, it will find it online

Go back into the BIOS / UEFI and re-enable secure boot

Congratulations! – You are running Windows Enterprise on your Surface PRO