This link: https://www.zdnet.com/article/heres-how-you-can-still-get-a-free-windows-10-upgrade/ describes how to upgrade to Windows 10 for free. I recommend reading through the entire thing. For example, it says that you should upgrade your drivers and any BIOS updates before upgrading. (Not sure that that's strictly necessary, but may be good in any case.) You can do a full back-up of your hard drive prior to upgrading, in case something goes wildly wrong. You can download and run Clonezilla from https://clonezilla.org and burn it onto a DVD or a bigger-than-4GB flash drive and booting into it. You should have an external hard drive at least as large as the hard drive you'll be backing up. (You can also back-up to a separate partition if you have enough disk space. I don't recommend this because you'll only be able to back-up the partitions, not the entire disk. If you do want to do this, you can use Windows 7's built-in Disk Manager to create a separate partition and use Clonezilla to back-up to that.) Note that Clonezilla is a bit non-intuitive, but it is a free alternative. You can follow the directions at https://clonezilla.org/fine-print-live-doc.php?path=./clonezilla-live/doc/01_Save_disk_image/00-boot-clonezilla-live-cd.doc