Assume that you have a Windows 7-based system with system restore points set, and the computer is upgraded to Windows 10. When you try to restore the system to an earlier restore point after the upgrade, you discover that you can't do that. The option is disabled.
Windows 7 Disk Size:
Restore points on Windows 7:
Restore points after you upgrade to Windows 10:
Querying the System Restore via PowerShell:
This issue occurs because system restore points don’t persist after a Windows upgrade. This behavior is by design.