Rawknrod,
Guitar Rig came with your copy of Studio One 2 as part of a bundled package. This bundle is from Native Instruments and when you installed it, you created a user account with NI. You should double check to see if your version is up to day by logging into your NI account and using their Service Center software to make sure you are on the latest version of their software.
To be clear, Studio One 3 does not come with Guitar Rig bundled with it.