Recommendation: If your PC came with a pre-installed version of Windows 10, make a full system image backup. You will also need a new legal Windows 7 copy (DVD), with an activation key. I take absolutely no responsibility about ANYTHING. NOTE: This is just a theoretical description, on how to do something in theory. This is a Kaby Lake based PC and I expect that many, if not all, of these steps can be applied to many other Kaby Lake based PC's. This is a guide on how to install Windows 7 64-bit version with all its essential drivers on an Acer E5 575G 54T8 Laptop.