Help recover lost HD space So I used to get the BSOD I was only able to fix it by reinstalling windows in my admin account I have 2 HD's (drives C and D), the smaller one( D) had recovery tool that I think it reinstalls windows but i dont have the windows disk because I bought this thing refurbished so when i reinstalled / recovered windows to factory setting i lost around 20GB!!! I used windows explorer and saw that i lost none of my custom folders under my administrator account yet when i tried to access the folders it was unaccessable. I got over losing my precious music and photos. BUt when i tried opening microsoft office it didnt let me. Soo...i used my cd-key( teacher and student edition with 3 licenses) and instead of fixing theprogram files it used the 3rd license nad i had no choice but to activate it!!! So i got over that too but the missing 20GB's are bitting me in the **** rite now...My system has slow down in performance and its notbecasue of viruses and such fragmentation plus im down to 15GB!! So..I am down to 15GB and want to reformat my main dirve (C) for a fresh install but I dont know if i'll be able to use the my cd-key and i dont wanna buy another one!!!So is it safe to reformat or should i contact microsoft?? THank you!!!