Toshiba Satellite fails to boot after NS install

Purchased a Toshiba Satellite L15W-B (this is the 2nd I've acquired).  Comes preloaded with Win10/McAfee.  I initialized the device; and then accessed my Norton account and downloaded/installed Norton Security and Backup.  Took three PC Restores to isolate a problem with NS as the cause. 

Also, I've been a Norton/Symantec supporter since Norton Utilities for DOS...

Here's the approach:

1) normal pc setup, created restore point then downloaded and installed NS.  NS requested McAfee removal so launched that process.  Completed the install and attempted a reboot.  Reboot failed at POST and could not load windows.  Had to use the initial PC Restore to re-access the PC.

2) Same approach as above but this time, installed DropBox and Google Docs/Chrome.  Created restore point and rebooted without problems.  Installed MSOffice and rebooted without problems.  Created another restore point.  Then, uninstalled McAfee and rebooted without problems.  Tested the restore points using Toshiba's restore process and worked perfectly.

3) Then, launched Norton Installer, rebooted, and boot failed. Attempted to access a restore point but all previous restore points no longer existed.  Were preset before Norton's installer and reboot.  Had to again launch the Toshiba System Recovery option and reinstall Windows.

I have reloaded everything accept NS and accessed this forum using the PC being discussed.  Will ot reload NS on this Toshiba or any other device until I can isolate the cause and solution.  Each system restore takes 2-3 hours and is time consuming and costly.

QUESTION:

1) Is this unique to the latest version of Norton Security with Backup?

2) Is there a pre-cleaning tool that will mitigate trace files from McAfee that might be resident?

3) Has anyone else experienced this and found a solution.

Thanks in advance for any suggestions.