How to update v1.7 to v1.8?

I am not sure how to update my current version which is version 1.7 with an expiration date of March 21. When I use the check for updates… feature, it shows I am currently running version 017 and that an update is available for download.

Where do I find this update? The Scrivener Windows download page only offers up the same version that I am currently running. I see posted here that version 1.8 has been released and people are using it. Confused.

This thread gives details on how you can download 1.8.