Windows 10: Prevent Accidental Deletion

What's the easiest way to protect a file from accidental deletion? I'm looking for something similar to setting "Read-only" in Properties.

:)

 

I accidentally downloaded windows 10, where can I find and delete these files?

I accidentally downloaded windows 10, where can I find and delete these files in order to prevent accidental installment bu Window Update??

 

Repairing the System Without Losing Data or Changing Any Settings

System folders are protected by default to prevent accidentally deleting of system files. Windows.old too is a component of System files. You should usually be able to delete everything except contents of C:/

 

Umm, never mind. Shortly after posting, I searched the Internet one more time, and I found instructions for either W7 or W8, and they were close enough. I forgot exactly what some of the things I clicked were called, but if anyone wants to know, I'll find the exact steps and post them.