GetWaikTools is a tool to grab the Waik/ADK tools (if they are not already available, they correspond to the note on the tutorial you followed:
These next notes you can largely be ignore unless you have problems: For whatever reason, when I use Win 7 32bit as my build platform, the Retrieve Tools or preconfigure scripts seem to just find bcdedit.exe without my intervention, but if I’m building on a 64bit system I have to copy bcdedit.exe manually into tools. Also, many instructions out there seem to indicate you have to copy these files:
C:\Program Files\Windows AIK\Tools\amd64\
depending on build platform. Copying them manually seemed unnecessary for me, some pre-configure script grabbed them for me automatically when I did my first build as long as I had WAIK installed. Your mileage may vary, so check with the Reboot.pro forum’s build instructions if you have issues as I can’t really troubleshoot for you remotely.
Can't say specifically on Win7PE_SE, but basically you are missing some needed files, you should be able to get around the issue getting the files manually and putting them in the folder according to the tutorial.
GetWaikTools you can get from here:http://www.msfn.org/...-the-huge-isos/
Make sure to use the Waik/ADK files for Windows 7 (and not the ones for 8 or 8.1/later).