It is installed and the addonmanager 3.1.0.1 shows that the product is active. It used to be I could load GSX by going to Add-ons, GSX, Activate
If you chose to install such an old version, it's normal nothing will ever work, since it's several years old.
The current version, which is the only available on our site, it's 4.5.0.10 but, considering it looks like you are using very old installers, it's probably best if you just download the latest installer for every FSDT product you have, without worrying about the Addon Manager, since all installers comes with it.