Quote:The upcoming Windows 10 May 2019 Update, also referred to as version 1903, will be blocked on computers with USB devices and SD cards attached.
 
Microsoft explains in a technical advisory published on April 24 that installing the May update when an external USB device or SD memory card is attached to the computer fails with the following error:
 
“This PC can’t be upgraded to Windows 10. Your PC has hardware that isn’t ready for this version of Windows 10. No action is needed. Windows Update will offer this version of Windows 10 automatically once the issue has been resolved.”
 
As for the reason why Microsoft doesn’t allow devices with external USB drives or SD cards connected to update to version 1903, the company claims it’s all related to the way drive reassignment takes place during the upgrade.
 
“Inappropriate drive reassignment can occur on eligible computers that have an external USB device or SD memory card attached during the installation of the May 2019 update. For this reason, these computers are currently blocked from receiving the May 2019 Update. This generates the error message that is mentioned in the "Symptoms" section if the upgrade is tried again on an affected computer,” Microsoft explains.