oh, I would like to add that I think you are a computer newbie? Am I right? Aha?
If you concerned about your data security. You can do a backup fisrt.
Win 8 pro has a built-in one. You can also use the thrid-party one.
Have you ever known Ghost? It's afamous backup tool. I used it long long ago, but not now.
I suggest you use Aomei Backupper now.http://www.backup-utility.com/download.html
Why? There's no reason.
Just because I'm its fan now.