If you already use Virto Gantt Web Part and need to upgrade it to the latest version, download the.zip file from http://www.virtosoftware.com. Unzip the file and run setup.exe as it is described in the Installing Virto Gantt Web Part section.
On the step 3 check the box “Upgrade” and click “Next”.
Note: if you have activated Virto ONE license, you do not need to activate it now.