Up to date WES7 Images for X90M7 / 0xc0000428 error using Windows Update

We have some old X90M7 we would like to use for some employees to work from their home offices during the corona crisis.

Trying to bring the old X90M7 back to life I tried to update the WES7 installations using Windows Update, a way I used successful in the past for similar devices. But this time I always run into a problem installing the latest updates, which results in a 0xc0000428 error from the Windows Boot Manager at startup.

Identifying the update which is causing the problem is a bit time consuming. That's why would like to install a newer base image from Wyse / Dell, then the one currently installed, but these images don't seem to be available anymore.

Does anybody have an idea, where to find newer images for these old devices, or at least original images, which can be pushed to different devices without a security key error?

Best regards from Germany and thanks in advance

Markus