Hi
Download and install, EaseUS TODO backup.
It's very easy to use, it will create it's own recovery disk that will boot your computer and it's free.
What you need to know is that you need to save the backup on another drive or partition not the one you are backing up.
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If you don't have a second hard drive or partition you might want to get an external USB hard drive so you have someplace to back things up, you should have one anyway if you have things on your computer that you don't want to lose.
http://www.amazon.com/Passport-Ultr...426048562&sr=1-1&keywords=external+hard+drive
Before you do the upgrade make a backup of your system and create the recovery disk.
As for stability while there are a few bugs and it's a work in progress, it's the only OS I have installed on my computer and I have all my software and games running in it.
I do make a backup of my system before every update just to be on the safe side.
The best answer is to dual boot with your existing OS, to do that you will have to create a new partition or about 150 gigabytes on your computers hard drive unless you have 2 hard drives.
Then do a clean install on it.
http://www.howtogeek.com/197647/how-to-dual-boot-windows-10-with-windows-7-or-8/
If you don't feel confident doing that then it's probably better to just backup your computer and upgrade.
Mike