I needed to remove ei.cfg since I will be using my windows 7 pro key.
steps I used:
ran the tool against the Windows 7 Ultimate iso
uncompress the ISO into a folder in the HDD. I cannot see traces of ei.cfg in the sources folder. I used Explorer and command prompt for the presence of the file.
Created a USB installer using rufus and Windows7 USB/DVD download tool and the ei.cfg is present.
I know it's easy to remove just ei.cfg once I created the USB installer but perhaps I'm doing it wrong? Thanks