It will have a recovery option which could send it back to as new condition.
You'l lose installed programs and files need to be transferred to an external drive or other back up (you should be doing anyway).
That's probably worth doing but at five years old things have moved on and you get excellent value for money on new machines now.

You might consider a new one with an SSD for the operating system.
The only issue is Windows 10 is about to be released which is generally looking like what you will want for the next few years.
If you got one now on 7 or 8.1 it will be a fairly simple but major update to 10.
The download is more than 2GB though.