[German]German blog reader Tibor simandi Kallay has sent me an e-mail alert about a problem when upgrading to Windows 10 May 2020 Update (version 2004). The upgrade fails at 30% of the installation with a message about invalid registry paths. Here is a description of the problem and the solution.
The error description
Tibor simandi Kallay wrote in his mail: On a number of my PC’s there was a strange error when upgrading to Windows 10 version 2004. The partition “System-reserved” contains the boot manager (cmd as admin, bcdedit) and at the same time this partition is assigned a drive letter (B:). Furthermore this partition is active so that the system can boot from it.
Tibor simandi Kallay could not find out why the partition has a drive letter – but there have been updates in the past that assigned a drive letter to the partition.
But when upgrading an existing Windows 10 to the May 2020 Update (version 2004) the process failed. After copying the files, Windows must install the updates. This is indicated by a display in Windows PE in white letters on the blue background. During the message “Updates are processed 30%” the following error message has been shown:
“The system registry contains invalid file paths. Installation cannot proceed. This system image was applied without guaranteeing that drive-letter assignments would match across computers.”
If the user clicks on Okay. this leads to a restart and the message appears:
Any changes made to the computer will be undone…
After half an eternity a restart occurs and after that the user will find his old Windows installed again.
The solution for the upgrade problem
An administrator must delete the drive letter of the System Reserved partition before upgrading. This can be done from the Disk Management – Change Drive Letter or Path branch in Computer Management. Then the upgrade should go through without problems.
Furthermore Tibor simandi Kallay wrote to me: By the way, it’s good that even PCs which are not yet offered the upgrade will survive the procedure without any complaints if the update is done with the Microsoft Update Assistant, which can be downloaded here. Of course you should do the usual things before that:
check all media
Drive C: Clean up
execute sfc /scannow
DISM /Online /CleanUp-Image /RestoreHealth
Unfortunately, Microsoft never checks the last point in particular. However, you can do this as a user by right-clicking on the My Computer icon and selecting Properties from the context menu. In Advanced System Preferences, select the Environment Variables button. In the displayed dialog box the entry Path can be selected under the category System Variables.
Via the Edit button a dialog opens in which the value of the variable can be adjusted. Sometimes you will find entries that no longer exist or duplicate entries, writes Tibor simandi Kallay. These should be checked or removed before the upgrade. At this point I would like to thank the blog reader for pointing this out, maybe he helps those affected.