Testers have tried to upgrade to the latest version of Windows 10, but they are facing some problems when doing this operation. The computers are being blocked from executing the command if they have an external USB or an SD card plugged into their PCs. The Windows 10 May 2019 is still in final testing and will be released in May.
Why Is the Upgrade Being Blocked?
The problem seems to be when all drivers have inappropriately reassigned different letters when external devices are connected to the computer. As you have observed by now on your Windows, the system is giving letters to all the intern or external drivers: hard drive, SSD, USB or SD cards. When the process of upgrading is taking place, those letters can be changed, but that’s the moment when the problem appears.
Nevertheless, to say, the real problem appears when the internal hard drive is affected. The external ones can be remove easily. If this happens with your internal hard drive, if the update is reassigned you a different letter, the damage caused can be significant. Imagine the worst scenario of your computer looking for files on a specific drive, but the files are no longer there because of the modified letter. Because of that, Microsoft has blocked all the upgrades to the new version, especially for the computers with USB devices attached. If you still want to upgrade your OS with the latest version, remove all your external devices and cards, and restart your PC. After that, the Windows 10 May 2019 should become available.
Finally, Microsoft has declared that these issues will be resolved with a future servicing update for Windows 10, and the testers have the issue fixed in build 18877. We are hoping that Windows wouldn’t make the same mistake this time like the one made with October 2018 Update.