And Windows provides two built-in features to make a bootable external hard drive. How to make a Windows 10 bootable external drive? There are four methods for you. How to Make External Hard Drive Bootable Windows 10? If you need to use a computer, but the computer is not around, then you can use the bootable drive to start other computers and use your own operating system anytime, anywhere.When your Windows 10 fails to boot due to system corruption, hard drive failure, or a virus attack, you can easily boot your computer using the Windows 10 bootable external hard drive you created earlier to avoid being unable to use your computer at important times.There are a number of important reasons for users to make external hard drive bootable Windows 10. Why Do You Need to Make External Hard Drive Bootable Windows 10? Make External Hard Drive Bootable Windows 10 FAQ.