Hi and welcome to the forum
I'm not an expert on this, but I do have some experience as I had customers using Spanish language and keyboard on W7 & W8 machines. Others may have a better solution and they will chime in hopefully if they do.
The question that comes to mind here is that when you ran the W10 AU v1607 upgrade, did you remember to select the native language
AND keyboard layout in the W10 install program to English-US? If you did, and it is still failing, that's most likely a fault of the v1607 update itself and there is no fixing that. 99% of the folks here and in my customer base who attempt a W10 pre-AU upgrade from either versions v10240 or v1511 have 1 or several glitches, and this could be one that I have not yet heard about-and we've seen hundreds of different ones, fail. The only solution I can offer at this time, is that because of the huge number of failures with the v1607 update is that we are advising people to backup their computers, and download the MCT tool directly from Microsoft website here:
Link Removed
This tool will provide bootable W10 install media on either DVD or USB stick, and what's required is called a CLEAN INSTALL of W10. Retest your computer and see if the problem is solved. If it is; you are now on v1607 and all set to go!
Reinstall all your programs and copy your data back over from external media and you are golden.
Let us know if that works out for you, and sorry you are experiencing problems with the AU v1607 update.
Best of luck,
<<<BIGBEARJEDI>>>