I picked up the 5th Anniversary Oblivion Steelbook (domestic North American version, if it's relevant) amongst a mess of clearance items at a local big box store for $10 a little over a month ago (mid-January). I haven't installed it as of yet, which is what's prompted me to inquire about a technical detail that I hope will not be too much of a groaner.
I'd like to keep the Steeler in as good condition as possible (so much stuff in there, the map & manual and everything; it's a business to get the darned thing closed without intentionally slipping on the plastic cover to do it!

My question, barring any longer a message, is thus: when fully installed, what of the two DVD-Roms (I know the 3rd disc is a video DVD) used in installation of the 5th Anniversary Edition are needed afterwards for playing the game once properly installed?
Thanks for listening!
-Boe.