Need help finding audio drivers  

My sound is working but "line in" and stuff wont show up in sound. So i have sound but no mic. The driver says its a microsoft driver. The sigmatel audio drivers i tried using were all distorted when i installed them as in the sound would work and everything would show up in Sound but was messed up. Its obviously the wrong driver so i uninstalled it and put the "Microsoft" one back. Any help would be awesome, thanks.

Gateway 840gm (slightly upgraded)
500w power
Nvidia 9800gt gfx
3gb ddr2
3ghz pentium d (dual core)
125gb hdd
Windows 7 ultimate 32bit

I think its because the newest drivers i can find for me is 2006 for windows XP, but i will try doing what you said because i didnt try that.

*edit*
Yea that didnt work it was already set to DVD quality. Im just going to go out and buy a compatible sound card because my computer is old and i dont feel like dealing with this lol.

Yea i think maybe im just screwed and need to buy a new sound card. I tried running it in compatibility mode with the recommended drivers and the same thing happened with the sound sounding distorted/slow and what not.

Its weird when i install the drivers line in, and all the other stuff shows up but says nothing is connected (even though it is). My headphones dont show up either. When i use the "Microsoft" one that the scan for new hardware installs after i remove the xp drivers works the sound flawlessly but the line in and my other stuff doesnt show up so i cant use my mic. I will still probably just get a new sound card instead of these old intergrated one. Thanks for the help anyway guys.