Hope that you attempted 'System Restore' using a different 'restore point'. The 'Restore Point' that you used previously may not have been 'healthy'; therefore did not lead to restore completion. If you are unsure about it, you may attempt 'System Restore' again using another 'Restore Point'.
Glad that the 'Hardware Diagnostics' passed; 'hardware' looks good.
Please share if the system allows you to boot to 'Safe Mode'. If yes, please keep a 'back up' of all personal data on an external media.
Do reply with the results; will take it forward.