Before proceed with driver installation, just try this drivers first:
1. Conexant_acer_win7 : Download
2. Since the signature is AC97, give a try with realtek AC97 drivers : Download Link
Install by right click and select run as admin.
Method 1 : Edit the inf file.
I already write a brief instruction about this for universal notebook driver conexant audio installation.
You can read here for the installation with pictures.
Method 2: Compatibility
1. Download your original Windows XP Drivers.
Conexant Version : 188.8.131.5235 : Download
2. Extract the driver file and select "properties" and select "compatibility". Tick "run this program in compatibility mode for" select Windows XP. Apply and OK. (example with pictures here).