Before downloading this version, open PediTree to look at the copyright date in your name & address panel. If it is 2015 or later, then continue with these instructions. If 2014 or earlier, then you need to pay £12 for a new CD or £10 for web only.
If you have received the password from Pedigree Software, then click on this link and Save the .exe file. Note the filename is pt3345.exe, with the intention that you can more easily return to an older copy if you hit problems.
It is a PediTree Update Setup Wizard .exe.
Then you can Run it and extract to c:\pedigree
PediTree should not be open when running the installer.