Are you still on Windows 7, 8 or 8.1? Do you intend on using your computer past January 14, 2020? If so, this news applies to you: the last remaining loophole that one could use to get a free upgrade to Windows 10 will be closing at the end of this year (Decmeber 31, 2017). Windows 7 reaches "end of life" (EOL) on 1/14/2020 after which it becomes unsafe to have your computer connected to the internet. As we saw with Windows XP, once a Windows version reaches end-of-life we see a flood of exploits that malicoius hackers have been keeping in their pockets, waiting until that point to reveal and use them since they know after the EOL date Microsoft will not fix the flaws in that version of Windows.
If you're interested in taking advantage of the free upgrade, I encourage clients to bring me on to assist as there can be more to deal with besides the seemingly-simple install process. Your computer might really need more memory (RAM) to perform decently after the upgrade. A larger or faster hard drive might also be worth considering. Then there are Windows 10 drivers from your computer manufacturer that might need to be installed manually after the upgrade... these do not get installed as part of Microsoft's upgrade process.