Question about reformatting

Greetings,

I built this computer back sometime in 2012 and need to reformat. However, I'm wondering if I will need my disc or key for Windows 7 for it after I do so..

I've searched high and low and cannot find either of them. Really would hate to have to go buy another copy. :(


Also, is there any way to backup my World of Warcraft WTF folder so I don't have to deal with redoing all of my AddOns again.