The best and most secure way to do this is to edit the Hosts file in Windows 10

The Hosts file is located here:

C:WindowsSystem32driversetc

I have prepared a hosts file for you which will block all websites but the ones you want listed, open that file and edit it in Notepad, then replace the original Hosts File in Windows . . .

https://www.dropbox.com/s/f2iep9qnue194p7/Hosts?dl=0

At the top of that file you must list any websites you want to let through

#allowed sites
173.194.33.128 google.com
#blah blah, more sites here