Steady as you go there KIO: Windows 10 update error leaves users stuck in reboot loop http://www.wired.co.uk/news/archive/2015-08/11/windows-10-update-error I've reserved my copy, but won't be making the changeover until they've ironed out all the creases.
Instead of using the update via windows update Use this & create a bootable USB drive. Much safer & if you get a boot loop you've got bootable media to fix it. You'll need an 8gb or bigger drive. https://www.microsoft.com/en-us/software-download/windows10ISO Top tip partition your drive into say 100gb for Windows and the rest as second volume. Once windows installed create my documents folder on 2nd volume (the big one) and point all the my docs library at it. This keeps your documents away from the OS, this way if you need to reload windows at any point you can wipe the OS partition without losing your data
Actually apart from the start button malarkey Win 8 is/was pretty impressive effectively Windows 10 isn't that different again start menu aside. Win8 introduced the Windows store, much better task manager, start search for quickly launching programs and the improved file copy display & lan transfer speed is vastly better than 7. Not for all users but Windows Storage Spaces is absolutely fantastic.
In my computer you have your hard drives listed. When you start installing windows you get the option to divide your hard drive into different size units (partitions) You can have say a 500gb drive you could divide it into 100gb & 400gb which would show as drive C & D You'd then install Windows onto the smaller partition and all your personal stuff like letters, photos etc you'd store on the larger partition. That way if you need to reload windows all your data is tucked away on a separate area. Think of it like having folders in a filing cabinet one for "work" & another called "personal" it's just a way of keeping your stuff away from operating system stuff