Win 10 1903 May 29, 2019—KB4497935 (OS Build 18362.145) still fails the update from a USB stick.

(1) I edited my prior post with the outcome of the over-install of 1903. It went well. Thanks for the heads-up.

(2) I created the Win 10 USB Installation media using MediaCreationTool1903.exe. It was a fresh download of the tool, & it fetched the new 18362.175 OS Build (instead of the 30). The first try produced the same error message reported on page 1...

I think your work-around sounds like it should work. But I have a qualm that copy/paste might miss something - a super-hidden file or something else that the MCT must do to make the USB drive boot properly. Anyhow, it was only 2 tries this time. Thanks.

PCR,

The problem with windows 10 MCT is that it goes through a download process each time.

There is no point of downloading again. After you have the ISO file you can build either a USB stick or a DVD from it, without using windows 10 MCT.

The tool they had for windows 7 was much better because it had the option of building the installation media from the existing ISO file, the win 10 MCT seems to be going backward.

As for copying all the files and folders, just make sure the file explorer is set to show all hidden files.

For compatibility with UEFI and Legacy Bios the USB stick must be formatted as FAT32 and the partition must be set active.

The old Windows 7 tool was formatting as NTFS which works fine for booting with Legacy Bios, but may not work on new UEFI.  Some older machines running in UEFI mode may boot also from a stick formatted as NTFS, but FAT32 is a requirement for UEFI.

All they needed to do was to update the Win 7 tool with an option to use FAT32 and it would work much better than the current Win 10 MCT.

B.T.W.

I tried to create the USB media installer with Win10 1903 MCT and it worked fine for me on first attempt.

(1) I edited my prior post with the outcome of the over-install of 1903. It went well. Thanks for the heads-up.

(2) I created the Win 10 USB Installation media using MediaCreationTool1903.exe. It was a fresh download of the tool, & it fetched the new 18362.175 OS Build (instead of the 30). The first try produced the same error message reported on page 1...

I think your work-around sounds like it should work. But I have a qualm that copy/paste might miss something - a super-hidden file or something else that the MCT must do to make the USB drive boot properly. Anyhow, it was only 2 tries this time. Thanks.

"The .ISO got made first try. The USB took two tries this time (instead of 3). On the 2nd try, all was the same, except I deleted both $Windows.~BT & $Windows.~WS first. Those are temporary folders that appear whenever MCT is run."

PCR, 

I don't understand what you do to create the USB media.

Once you have downloaded the windows.iso it is easy to create the USB directly from the .iso file without using MCT again

All you need to do is:

1. Format the USB stick as FAT32 using windows. That puts the BOOTMGR on logical sector 0 of the volume. Make sure the volume is marked as Primary partition and Active.
2. Open the windows.iso file with windows explorer and then copy all files and folders from the opened iso to the USB.  The USB media created that way is bootable on either UEFI or Legacy Bios machines.

BenjunHe, 

Do you have a question ?

The new Windows 10 1903 Installation media at build 18362.175 has the fix for the USB problem described.

According to the description of the fixes in KB4497935 the bug with the USB devices should have been fixed, but it still does not allow updates with installation media on a USB stick.

Fix description:

"Addresses an issue that may cause an external USB device or SD memory card to be reassigned to an incorrect drive during installation. For more information, see "This PC can't be upgraded to Windows 10" error on a computer that has a USB device or SD card attached"

I tried to do an update with installation media build 18362.145 on a system already at 18362.145 and still gets the error message below:

 

Is there a fix yet for this bug in the v 1903 release ? Which build do I need to get this bug fixed ?

I know that I can work around the issue installing from a local drive.

Also if I try upgrading from1903 to a preview 20H1 build 18908.1000 using a USB stick the update completes without this message.

I hope we don't need to wait for 20H1 to get this bug resolved.