Need help udpating my sound card/drivers

I have been having issues on runninga game, when i asked for help i was constantly told to update my graphics and sound drivers, i updated my graphics driver but that didnt fix it, so I tried updating my sound driver/card, but now i cant even launch the game (or any game) without it crashing instantly, aslo, I dont get any sound while trying to watch videos... this is the first time i have tried updating my drivers so im sure i made some stupid mistake somewhere, so please help me figure out what to do.

My specs from Xfire:

Manufacturer:Alienware
Processor:Intel(R) Core(TM)2 Duo CPU T9500 @ 2.60GHz (2 CPUs), ~2.6GHz
Memory:4094MB RAM
Hard Drive:306 GB
Video Card:NVIDIA GeForce 9800M GT
Monitor:Generic PnP Monitor
Sound Card:Speakers (2- Realtek High Definition Audio)Speakers/Headphones:
Keyboard:USB Root Hub
Mouse:USB Root Hub
Mouse Surface:
Operating System:Windows Vista™ Home Premium (6.0, Build 6001) Service Pack 1

Need your motherboard name, as it is onboard audio. What kind of problems?

eh... where do i find my motherboard name? Im using a notebook, if that matters at all.
And the problems are that all my game crash now... not just the one. and there is not audio whatsoever on my comp anymore, videos are just silent now.

If its an Alienware machine, just ring them up and complain.

actually i got the download for the sound card off the realtek site, vista/7 download too.
and i got newgraphicsdrivers earlier that day, still re-installgraphics drivers?