The system requirements published by Adobe indicate that Windows 10 is required for Lightroom CC.
Lightroom Classic CC will, however, run under Windows 7. Lightroom Classic CC is more robust as far as editing tools are concerned. And you still have the option to share collections via the Internet if you choose to do so.
So there is nothing available in terms of a subscription that will work with Windows 7?
Yes, there is a sub subscription plan that will work with Windows 7. It's the Creative Cloud photography plan, and you would have Lightroom Classic CC as well as Photoshop. Lightroom Classic CC is folder based, meaning your master files will be stored in folders on your computer. However, you will have the option to create collections that you can share in the cloud. Lightroom Classic CC is more like the Lightroom that has been around for a number of years. If you have used a previous version of Lightroom you would probably be more comfortable with Lightroom Classic CC anyway.
I guess I need to be a little more specific. Adobe has unintentionally confused the public. They have introduced a new cloud-based Lightroom that enables users to store their master images in the cloud and synchronize those images across their computer, their phone and all mobile devices immediately, and have a consistent interface across all those devices. When they introduced this new program late last year they named it Lightroom CC, the same name that has been used for Lightroom for the last several years. The Lightroom CC that we have known was rebranded as Lightroom Classic CC. The new Lightroom CC is in its infancy, and because the interface must be consistent across all devices is lacking a lot of features right now. That is expected to change as the program matures. It is this new Lightroom CC that is only compatible with Windows 10.
What some onlookers seem to regard as the "old" Lightroom is now Lightroom Classic CC. It is still being developed and is alive and well. This is the one that is still compatible with Windows 7. Both versions of Lightroom are available through the Creative Cloud photography plan. Since you are using Windows 7, you just install Lightroom Classic CC and Photoshop, and don't worry about the new Lightroom CC.
I don't know why you are hesitant to install Windows 10. The computer I'm using was purchased with Windows 7, and I have converted it to Windows 10 and have had no problems. But it's your choice. I'm not trying to persuade you to switch. In my opinion, however, there's really nothing to be afraid of.
It appears that Adobe has stopped supporting Lightroom CC for Windows 7. It used to run, because I was running the two Lightrooms side-by-side on Windows 7. Then I did a clean install of Windows 7 and only the Classic would install from the Creative Cloud app.