Turning on the built-in back up tool in Windows 10 only takes a few clicks. Not sure where to start when it comes to picking out a drive? We happen to have a list of our top recommendations. So, if your Windows 10 ( $148 at Amazon) laptop has 256GB of storage, you'd want a backup drive with 512GB of space. The unofficial rule for the amount of storage a backup drive should have is 1.5-2 times the size of your computer's storage. For either method, you'll need an external hard drive or SSD. Below I'll walk you through how to set up routine backups of your most important files, as well as how to create a complete copy of your system in its current state.