When I setup my Computer, I normally map the DVD drive so that it's near the end of the alphabet i.e. Y:\ or Z:\. Please check out the 2 images below and you will see why....
If you plug in a USB drive, I hate that the data drives that are not 'beside' each other.
If you don't know how to assign drive letters to your drives, check out this Microsoft solution:
Thanks to Lap Ho for sharing this tip.