No Sound after instaling new drivers

I was running win7 32 bit fine before with sound before insatlling the 64 bit version all fresh installs.
Now No Sound on Acer m1641 after instaling new drivers !!,
i have the realtek updated drivers that worked fine on the first install.
The ironic thing is that i have the 32 bit win 7 running fine on my hp notebook and it flies!

Do you know the model of the soundcard on the Acer m1641, as I can't find much information on that model.

The type of onboard soundcard you need is here.Try downloading the latest 32 and 64 bit drivers for Windows 7 from here:

http://www.realtek.com.tw/downloads/