This feature disables / enables the Windows Firewall (MpsSvc) service.
Check mark is set - the service is disabled, check mark is removed - the service is enabled.
Disabling the Windows Firewall service saves system resources.
Description of the Windows Firewall service from Microsoft, in Windows 7:
"Windows Firewall helps protect your computer by preventing unauthorized users from gaining access to your computer through the Internet or a network."
System reboot: not required
OS: Vista, 7, 8, 10