You can run any X86 version of Windows such as Windows 8.1 or Windows 7 on any Mac that has an Intel processor, which means that if your Mac was bought any time from 2006 onwards it is good to go with Windows. (See also: How to speed up a Mac.)
Why run Windows on a Mac?
There are plenty of reasons why you may wish to do so. OS X is great, of course, but there are plenty of professional situations where everyone else is using a Windows PC and it is helpful to be on the same platform. It means you can run the Windows versions of software such as Word, Excel and PowerPoint. Gamers can play the versions of games written for PC.
And the great news for Mac users is that only on Mac can you run both OS X and Windows.
How to run Windows on Mac: virtualisation
There are two ways to run Windows on Mac. The simplest is using Boot Camp, which we will show you in a moment. The other option is virtualisation.
You can use virtualisation programs such as VMware or Parallels in order to run any x86 operating system on your Mac, including Windows and Ubuntu Linux. Virtualisation is great because it allows you to run different operating systems from inside OS X. So you could put Windows 8 in your Mac's Dock, and open it as a window as required.
The bad side of virtualisation is that it is slightly more complicated to do, and it costs money. It also shares your computers resources across two operating systems, which can affect performance.
How to run Windows on Mac: Boot Camp
Boot Camp is the simpler option. And Boot Camp is a feature built in to OS X. In Boot Camp you switch from one OS to another - you can't access Windows from within OS X. But this means that all system resources are dedicated to the operating system you are using, which means performance should be better than with virtualisation.
Here's to use Boot Camp to run Windows on your Mac.
First, you will need Windows installation media - either a DVD or a bootable USB drive.
You'll also need to download and install to a USB drive the OS X Windows install drivers, so make sure you have a spare thumb drive handy.
Let's begin. Boot your Mac, and navigate to Applications, Utilities. Double click to open Boot Camp assistant.
Now set the partition size for a Windows installation. You'll need at least 16GB, but more is better here.
Now click the Partition button.
Your Mac will restart. Insert your Windows install disk, and the Mac will boot to the disc running the Windows installation process. You will be asked where to install Windows - point it at the Bootcamp partition.
Now click Drive options (advanced). With the Bootcamp volume still selected click Format.
Windows will now install in a process that will take a few minutes. When prompted, remove the installation media.
Your Mac will now boot into Windows. Now, whenever you open up your Mac, if you hold down Option you can select to boot into Windows or OS X.
And that is how to run Windows on Mac. (See also: Do Apple Macs need antivirus? OS X security explained.)