I am now downloading the update for Windows 10.
Since I have a copy of Windows 8.1 and an Intel-based MacBook I am able to run Windows in a virtual machine I use Parallels but there are other programs, some of which are free you can use to run Windows on your Mac.
From what I’ve read Windows 10 is quite an improvement over Windows 8. They’ve brought back the Start Menu, gotten rid of the “Charm” bar on the far right side and made quite a few other improvements.
Check out the review linked above for more information.