Okay, so I've gotten Oblivion for my PC, and I downloaded OBSE. Tried to run it and it said I needed to update Oblivion with the latest patch, so I downloaded that and Oblivion should be updated, however OBSE still says I need to update it whenever I try to run it. Does this mean that I haven't installed the patch? If so, how do I? Otherwise, how can I get OBSE working?

Which Oblivion distribution do you have? Oblivion GotY disc, Oblivion base disc, Oblivion GotY Steam, or one of the others?

Just the original base disc.