I do have 2 display cables on my monitor and both are hooked up to my computer. Starting from the OblivionLauncher is giving me the same error. I have the latest graphics drviers, but I don't know which other ones I need to update. I will try reinstalling it like that, I'm not sure why its in that weird location. What is UAC?
Don't worry about the UAC. You should never actually need to disable it, regardless of what anyone says. Nor should you disable it unless you are willing to take on 100% of the fault if something ever goes wrong in the history of your computer.
Just install the game anywhere BUT the Program Files folder. As suggested, make a folder called Games, or anything, and install it there (And all your future games as well).