I think it could be a simple case of driver re-installation.
I have put the file that you need (SD_AU8810_Win9x.exe - for Toshiba V3100 Onboard) into the Download section of this site
HERE.
You will need to do the following:
1) Download the file
2) Double-Click on it and extract it to a place you are gonna remember (i.e: c:\sounddrivers)
3) Click on "Start" > Run > c:\sounddrivers\AU10Setp.exe and follow the on-screen instructions.
Let us know how you get on.
