Getting hold of the Windows installer is as easy as visiting support.microsoft.com. Whether you've paid for it or not, Microsoft allows anyone to download a Windows 10 ISO file and burn it to a DVD, or create installation media on a USB drive for free. Once that's done, you can boot from your installation media and install. During the installation process, Microsoft will ask you to for an activation key. You can skip it at this stage and enter it once Windows 10 is installed. But eventually, Windows is going to start letting you know that your install isn't activated.

There are many ways to get a Windows 10 product key, and they range in price from totally free to $199 (depending on which flavor of Windows 10 you're after). You can of course buy a key from Microsoft online, but there are other websites selling Windows 10 keys for less. There’s also the option of downloading Windows 10 without a key and never activating the OS. But are you missing out on anything important if you don’t activate Windows 10? And will your carefully crafted rig face any risks if you go this route?