I lol'd at this.. This should belong in Help & Support. But this is an easily fixed problem...

Step 1. Download the FGunZ Client.

Step 2. Install FGunZ Client.

Step 3. Download the Updated Launcher.

Step 4. Go to your FGunZ folder in Program Files and replace the outdated Launcher with the updated Launcher.

Step 5. Delete the Launcher that came with the installation on you Desktop and create a Shortcut of the updated Launcher on the Desktop.

Run the Launcher and if you followed the Steps correctly, it should update and let you play. If this doesn't work, then something else is wrong, and it isn't FGunZ.