Windows 10: How Can I Stop Windows 10 from Rebooting Without my Permission?

This is the second time in a few days that Windows 10 has rebooted itself --for a virus definition update of all things... totally wiped out my working setup.. I had several open projects and a LINUX session in a VM. All that's wiped out.
I need to find a way to stop Windows from rebooting like this without my permission.

:)

 

Windows 10 permissions...

How is the NAS on windows 10 Pro? Is it software or a share? Did you check ntfs vs share permissions?

 

Windows 10 permissions...

Ok so I feel officially dumb I am trying to copy my steam library to my NAS. Both are on windows 10 pro and both have full control in the file manager. Neither windows nor fast copy will allow me to copy, both list a permissions error? This was never an issue with windows 7...so first off thank you microsoft god forbid I want to back up my data, second off what the heck do I need to do to make this work. All I could fine online was to set full control and that obviously didn't help.

Also robocopy doesn't apparently work with network locations?

 

Windows 10 Tweaks

Pressing “Windows+Pause Break” (it’s up there next to scroll lock) opens the “System” Window.

Windows 10: In the new version of Windows, Explorer has a section called Quick Access. This includes your frequent folders and recent files. Explorer defaults to opening this page when you open a new window. If you’d rather open the usual This PC, with links to your drives and library folders, follow these steps:

• Open a new Explorer window.
• Click View in the ribbon.
• Click Options.
• Under General, next to “Open File Explorer to:” choose “This PC.”
• Click OK

credit to Lifehacker.