Anti-aliasing tends to blur the heck out of some games.
It shouldn't. At most, the "blur" should never, ever be more than a single pixel thick. AA doesn't actually blur anything; it simply mixes the colors of more than one shape into a single pixel, because multiple shapes can overlap a single pixel. It should be more like a photograph in that way: If you look at a photograph on your computer, you will notice that it is fully anti-aliased; there are never jaggies in a photo.
But it may appear to be "blurring" to the untrained eye, so yeah keep that in mind.
Usually, what happens in anti-aliasing is that a much larger image is sampled down to the size of your resolution, so that you're actually seeing an image with a higher virtual resolution than the physical resolution.
Personally, I dislike the jaggies and always try to play games with anti-aliasing on.
From his description, however, it sounds like only certain things are blurry. Which tells me he's probably playing with something turned down.
Go to the "Options", click on the "Video" tab, and turn the "Video Quality" slider all the way up. That might help.
It could also be a low memory problem, so it's falling back to smaller textures - try turning off all unnecessary programs running in the background.
In addition, keep in mind that some things (such as movies) are recorded at a certain size, and if your resolution is above that size, it may actually be scaling everything up, causing it to be blurry.
I always recommend running an LCD at its native resolution, where one pixel on the resolution corresponds to one pixel on the LCD. Unfortunately, LCDs handle different resolutions very poorly.
Would it be possible to get a screen shot? Right now, we're just guessing in the dark. If we could see it for ourselves, we might have a better idea of what is happening.
Edit (becase some replies appeared while I was typing):
Monitor Name: Plug and Play Monitor - which means it is not specific to the display.
Problems sometimes happen because of incorrect timimgs due to an incorrect driver.
Umm, the GeForce Go 6100 is, I believe, a laptop video card, so it's an LCD, so timings are not applicable. But a poor driver may be making it go to a non-native resolution, perhaps?
