Nvidia settings missing from Display Properties

[phot0nic]

I'm current using an Nvidia Geforce 6600, with the latest version of the drivers. All is going fairly well with that, however, I can't access the Nvidia options anymore. I used to be able to right-click on the desktop > settings > advanced, and a tab would be there to modify my settings, but now the tab is missing. However, the drivers seem to be working fine because my 3D apps are just as fast and smooth as ever.

This probably has something to do with me disabling either a startup entry or a service, seeing as I like to cut down on things that don't have a direct impact on me. The only Nvidia processes I have coming on at startup are NvCpl and nwiz. The Nvidia entry in the control panel doesn't provide access to the options I'm looking for either. If anyone knows what's wrong, could you please point me in the right direction? thank you.