Fresh install of Win8 over Win7

Hello,

I held on to a copy of the $18 Win8 that was available earlier this year for when I want to install it.

Just want to clarify some basic stuff before I go ahead and install.

I have a SSD as C Drive and HDD as D Drive.

1. I want to use this copy to do a fresh install over the Win7, it has this option to do so right? I took a look before in February, but just want to confirm.
2. My files in D Drive will be safe? Or do I need to transfer them to an external HDD?