Well, I just got Oblivion on my Dell Inspiron Mini netbook with Windows 7 Ultimate, and whenever I click return in video settings the game CTD's, I was wondering if I can modify settings outside the game.

You're gonna need to give a bit more information than that mate if you want to get some help but on the face of it I'm not entirely convinced that a mini netbook is an entirely appropriate piece of equipment to be running a game like Oblivion on in the first place, to be brutally honest.
It's been known to bring fairly chunky PCs to their knees before now.
netbooks are not for games - certainly not games like this.

Also, you might wanna get this moved to the hardware/software forum, but I doubt you'll have much more luck there, to be honest...

I would be pretty surprised if you can get Oblivion to run on a netbook, but, then again, I've been surprised before.