Generally you want the boot drive to be C:. If you do a clean install of Windows 8 onto the new SSD with the old HDD disconnected, the SSD will be C: by default; don't try to change this!
After installation, move the DVD drive out of the way (rename it Z: or something), and reconnect your old HDD (which should become D:).
The years just pass like trains. I wave, but they don't slow down.
-- Steven Wilson