www.nhancer.com/
Using this I was able to enable both AA and HDR in Oblivion. There is a more specific method of enabling both in R6 Vegas with Nhancer.
However, I had a recurring error problem after a few minutes within Oblivion after a few minutes of play, after turning to my stock gpu speeds and insuring nothing was already enabled through the Nvidia control panel, the same problem kept happening.
I can't put my finger on it, but forcing the multisampling through the Nvidia control panel, I still felt like the jaggies were more apparent than using Nhancer... did anyone else have that feeling?