What Can You Do?
This flaw doesn’t need to be a deal breaker though. Using Windows Firewall, you can block a single program, or all programs, from accessing the Internet unless it’s done through a specified network type, such as a VPN’s Public network. That way, if the VPN disconnects, the program will fail to connect to the Internet, thereby preserving your privacy. After you reconnect the VPN, the program again accesses the Internet through the VPN.
However, for this approach to work, your home network (the connection to your ISP) and your VPN network must use different network types. Unless you’re on a domain, that means your VPN network should be Public, which it should already be, and your home network should be Private. If you’re unsure how your home network is configured or need to change it, see the previous article How to Configure Windows 8.1 Networks to be Public or Private.
Once you’ve verified the network types, you’ll need to block the program’s traffic through the Private network. Unfortunately, Windows Firewall uses separate rules for incoming and outgoing traffic, so you essentially need to follow the procedure twice: once to set up an Inbound Rule and once to set up an Outbound rule.
However, the procedure is relatively painless, so it’s no big deal unless you’re configuring a long list of programs.