By creating and saving an image of your HDD, you can quickly and easily revert your system to the exact state it was in, including all files and installed programs and settings. What I highly suggest is to learn how to create an image (or clone) of your hard drive (HDD). Now, pretty much everyone knows that you should keep a backup of your important files, and it's even more important to make sure you have a backup before doing an major OS upgrade such as this, so I won't get into all that.except to say that my suggestions below do NOT replace the need to keep traditional backups! What's your recourse when something like this happens? Some are lucky enough to be able to roll the upgrade back, but many folks with more serious problems have no choice but to do a fresh install of Windows, which can be a very time consuming process. While it seems that for most folks the upgrade to Windows 10 has been surprisingly problem-free, there are also quite a few posts on this sub from folks who had major problems and left a computer that wouldn't boot or start Windows properly.

Windows 10 bootable clone