You can adjust volumes using Windows' interface, but for EQ you're screwed, because Realtek only supports a few presets pre-built in cement with no flexibility.
In my opinion, you can get good EQ if you simply use the right playback software. FFDshow for audio and video is a good choice, the EQ module is scalable (you can pick your own bands and magnitude limits).
Krogoth: There may yet some still a stop-going or nasty bug creeping around [in Windows 7 RC].
Brian_S: Make no mistake, the GTX480 will be the greatest invention known to mankind.