Update to CIS 4 Question

Hi, i have an instaled version of 3.14 of CIS on my PC the firewall only not antivirus. Now that version of CIS 4 came out i have to unistall the previus version of CIS from my pc to upgrade to version 4 or CIS will update to version 4 it self?Cause when i try to upgrade it says no updates are available, thanks.