A VPN connection works like a tunnel over the public network, securing and encrypting the access for any of those who connect to it. Thus, your network resources will be safe from the eyes of unauthorized viewers, and only those who you grant access to it will be able to access the files. PPTP is one of the most common VPN protocols, which is mainly due to its ease of use and setup. In Windows XP, setting up a VPN connection using the PPTP protocol can be done using the OS’s built-in tools.