How can I know if my pc has the right drivers?

I'm new to linux, I got myself an Ubuntu 10.04

I think that the audio drivers aren't working well, since the sound is not as good as before (on windows). I also think the graphic drivers aren't working well, since the pc freezes after ubuntu login, if I set the "visual effects" on anything higher than "none".

I have a 945gct-m2 motherboard with the built-in graphic card and audio card.

How do I know if i have the right drivers, or check if the hardware is working correctly?

PS: remember that I'm new to ubuntu so I don't have all the knowledge required.

Generally speaking Intel drivers Just Work out of the box. Here are some things you can do to help diagnose the problem. In System -> Administration -> System Testing you can run the hardware tester:

From this menu you can run just the test you need for video (or you can run them all and submit them, which would submit your hardware information)

The Ubuntu X team has a whole set of pages on how to debug your problem, it sounds like the page for Intel Performance Problems might be a good place to start.