GeForce 8800GT & sound not working in 8.04

[phearsome]

Hello.
I recently got a new computer, and installed Windows XP and Ubuntu 8.04 Hardy Heron.
Well, everything works fine in Windows, but in Ubuntu neither my sound or my graphics card works.

I have tried using Envy for the graphics driver. It appears to install without any problems.
However, it doesn't appear in Applications, and when I try to run it through the terminal it says:

 /usr/bin/envyng: line 11: cd: /usr/share/envy: No such file or directory
Traceback (most recent call last):
  File "/usr/share/envyng-gtk/envynggtk.py", line 736, in <module>
    os.chdir('/usr/share/envy')
OSError: [Errno 2] No such file or directory: '/usr/share/envy'

When I try to install the drivers manually, it says I need to shut down X. How do I do that?

My sound card is integrated on my motherboard, MSI P35 NEO-F.

My hardware setup is:
MSI P35 NEO-F
Intel Core 2 Duo E6750 2.66GHz
GeForce 8800GT 512MB
2GB DDR2 800MHz RAM.

Grateful for any help, thanks in advance.

EDIT: I got the sound working, but I'm only getting sound on my left speaker.