Lol, well its too late here as I already downloaded the 1903 iso and had no issues what so ever upgrading over USB using my SanDisk Extreme 32GB thumb drive. I have 5 drives assigned their own drive letters and nothing changed at all. System is now updated all the way to b18362.53. Running great so far and I been running it since yesterday well over 6 hours now. I will give some feedback via the Feedback Hub if anything arises.