I need to update my Safari Browser, help!

I have a gateway desktop PC using Windows 8.1. I need to update my version of Safari because there are things I can't do until I update my Safari browser. Currently I have 5.1.7. Each time I download what I think is an updated version always comes out as 5.1.7. I am told there is a version 11. Is that true and how do I get it? Thanks.

Al Wallace