Yes. You can still upgrade to Windows 10, for free, from Windows 7. Provided your Windows 7 is genuine, and activated. Follow these steps, to get your free windows 10 upgrade.
Now, it should go without saying that prior to any big updates or upgrades, especially for an operating system upgrade, you should do a proper backup. I would advise doing a system image backup, or clone, as well as making sure you have all your files backed up. It’s worthwhile noting down your most used applications as well so that you can make sure they still work after the upgrade. If you’re worried, do a little check before hand. But for the most part, your applications should work fine on Windows 10. I’ve yet to find many (if any) applications that won’t work on Windows 10, that do on Windows 7. Windows 10 has a pretty good compatibility mode you can run applications in as well. Anyway. On to the upgrade.
I would advise doing this sooner rather than later, get off Windows 7 as soon as you can.