Can I do these things with Vista?

your processor is good, because dual core is apparently better for a lot of games. This is because certain games have not 'utilized' quad cores and so they run slightly slower even though they have a higher total frequency. The video card is pretty much ok, although if you wanted to play any next gen games liek crysis and fsx you'd need atleast an 8800gtx for smooth gameplay on adequate settings. And yeah, you might wanna upgrade to vista home-premium 64-bit. Because vista is more ram intensive than XP, you'll also need more ram, preferably 4gb or more. =]

Well, considering computer have been "high def" since the 1990s... I think you're covered on that one ;)

As far as latest games, well, I'd have to know specifically what video card you have because it looks like you're getting a very low-end GeForce card. But, if it's a dedicated card, you should be ok for most new games, but you'll probably have to keep the visuals on low or medium-low.

On a side note, I'd recommend the Q6600 2.4GHz Core 2 Quad over the 3.0GHz Core 2 Duo. Overall it performs MUCH faster and it's almost the same price.

I would look in to getting 4gbs of ram and Vista x64 then you will be able to play games for years to come. Remember that games will only become more demanding so by spending a little more now you will save in the long run. A 512 - 1gb GPU is also recommended.