Was reading your post and wanted to tell you how to do this. It is very simple.
First make sure all system files and folders are visible. Then go to c:\Cmdcons folder, find a file called txtsetup.sif. Search for a section called [NLS], under there you will see " DefaultLayout = 00000409"
Just change the number to what you want, save and when you reboot to test RC you will have the keyboard of your choice.