Internet Explorer 11 - Enable Protected Mode via Windows Registry using Ruby

# 1 - 'Intranet'
# 2 - 'Trusted Sites'
# 3 - 'Internet'
# 4 - 'Restricted Sites
zones = [1, 2, 3, 4]

# @see https://superuser.com/questions/1031225/what-is-the-registry-setting-to-enable-protected-mode-in-a-specific-zone
mode = 0 # Enable
# mode = 3 # Disable

# Build path based on zone
reg_path = -> (z) { "Software\\Microsoft\\Windows\\CurrentVersion\\Internet Settings\\Zones\\#{z}" }

# @see https://ruby-doc.org/stdlib-1.9.3/libdoc/dl/rdoc/Win32/Registry.html
zones.each { |z|
  Win32::Registry::HKEY_CURRENT_USER.open(reg_path.call(z), Win32::Registry::KEY_WRITE) do |reg|
    reg.write_i('2500', mode) # Write entry as Integer
  end
}