Well you could upgrade to windows 10 if you wish, that is down to personal preference.
Anyway if your system was pre built.
what you are looking for in windows is a third party restore and backup program, or one used to clone the hard drive that is installed on windows 8 ok.
Or you can use windows backup and restore within windows 8.
The hard drive you have is split into sections, and part of it is reserved with a snapshot or a save of when windows 8 was installed to your hard drive.
That part of the hard drive is hidden when in the windows os.
So you cannot see it, or click on it to accidentally delete the image, makes sense.
All you need to do is use windows backup and restore, or third party program and run it.
Select from image, or backup. file.
Then search your hard drive for a volume that says windows 8 ect.
The hidden folder will show.
Click inside the folder and select the .img file ect. click ok and next.
It will then warn you that all personal data such as pictures, documents will be wiped as a factory restore of windows 8 is about to install.
Just click ok let it do it`s thing.
And when the system restarts you will be asked to create a user account ect just as you did the first time you powered on the system after you bought it and set it up ok.