Version compatibility

I have a new Windows 10 laptop now running version 1.9.8.0. I have never updated the version on my older Win 7 laptop. It is running 1.7.1.0. If I upgrade, will I be able to open my older projects? One is a book still in progress. I need to be able to work on the same project on both laptops.

Thanks!

Scrivener upgrades your projects (creating a “backup” copy first), so you should absolutely upgrade to the latest version 1 release and get that part done. When v3 comes out, there will be another update to the project format, but it may only work with the project format used with the most recent v1 update.