bullet,

1. make a new scene
2. make a poly cube and select it
3. press ctrl-a and then select the mesh smooth tab
4. now with the cube still selected press the page up and page down button
5. you should see the sub division level (which by default should be 2) increase or decrease as you press the page up and down buttons


If you are not then something is wrong. If you are and things are still not smoothing then you have something wrong. If the subdivision level number goes up and down and you are getting error messages then ...you guessed it something is wrong.

But for all the time we are spending jumping through flaming dagger hoops you could have uninstalled and reinstalled maya about 5 times now. lol

If it still does not work with a clean install of maya then you have a os issue, gfx card issue, virus issue, driver issue, or your machine is just cursed.