For Ivacy Client
If you are using Ivacy desktop software, you will need to go to Dashboard tab and simply select your desired protocol from PPTP, L2TP, SSTP, OpenVPN-UDP, and OpenVPN-TCP.
For Manual Connection
If you are using XP or Vista, you will need to go to Properties of your connection, and click on “Networking” tab. From the drop down menu select PPTP.