No, it's not at all necessary, was just wondering if it could be a firewall issue or similar. It sounds like your postgres server isn't running which can happen sometimes.
Click Start --> Programs --> PostgreSQL --> Stop Service, then Start --> Programs --> PostgreSQL --> Start Service to restart PostgreSQL. If PostgreSQL does not start properly at this point and PT3 doesn't start working, go to C:/Program Files/PostgreSQL/8.x/data and find the file named postmaster.pid. Once you find that file, delete it, then attempt to restart PostgreSQL as above, and it should start properly.
If this happens every time your computer starts, you should set PostgreSQL to start automatically when your computer boots. See
Setting up PostgreSQL to autostart for more information.