Download Steam through its official website after successfully installing Windows 10 on your Mac.The rest of the process is self-explanatory since you’ll be prompted with screens asking about your system and user preferences while Windows 10 gets ready to boot in the background.Though this is up to personal preference, we recommend allocating at least 20GB of space for a little bit of freedom inside your new OS. The setup process will now ask you how much hard drive/ SSD space you’d like to reserve for Windows.
Simply find the ISO file you downloaded and choose your USB stick from the list that should appear after selecting the file.
If you don’t have a DVD driver to connect to your Mac, you’ll need a USB stick with at least 5GB of available space.Follow the instructions to save the ISO file to your Mac, and you’ll be using it shortly in the following steps.