If your job is to prepare Windows 10 images for reimaging & deployment, you may be familiar with the following errors. 

A fatal error occurred while trying to sysprep the machine.

Sysprep was not able to validate your Windows installation.

 

 

These are known Microsoft issues caused by stuff being automatically downloaded and installed from the Microsoft Store during the image creation process. Refer to the following Microsoft articles for more information.

• Sysprep fails after you remove or update Microsoft Store apps that include built-in Windows images
• Cleaning up apps to keep Windows 10 sysprep happy
  • There is a link to a zipped powershell script provided at the bottom of the article which works to clean up most of these errors. There is also a comment regarding registry changes which will prevent the updates from being pushed in the first place; those need to be added prior to connecting your build environment to the internet.