Hi Dave, its not only the OS that is needed to support DirectX11,12 but also your graphics card, do you know if your graphics supports it? If yes, then the next thing to do is find out if your computer will run Win 10, if there is Win 10 drivers for all your hardware, memory requirements etc. What software are you running now that might not be Win 10 compatible (older versions of photoshop or dvd software for example or similar).
I haven't seen what Microsoft are offering yet through their icon, if it is just an upgrade, or if it is a full version, but if it is just an upgrade version (meaning that you already need a version of windows installed on your computer first), here is probably and possibly one of the biggest traps for people in upgrading to Win10. If you are upgrading from Win XP or any other 32bit OS, all you will upgraded to is Win10 32bit, you cannot (using an upgrade version) upgrade a 32bit installation to a 64bit installation. To upgrade to a 64bit installation, you need to do a clean install of another 64bit OS to start with. You could download a Win7 64bit installation .ISO and install that without a product key and then upgrade it to Win10 provided that MS provide you with a Win10 product ID key so you can activate it, but as I say, I don't know yet what they are providing regarding their Win10 upgrade. I will be upgrading one of my laptops when I have some bandwidth spare sometime within the next week to find out more.
Cheers.
Edit: Several posts have been posted while I wrote this, so some of it is repeating what has already been said a bit. Sorry.