No Sound in Windows 8?

I have an ASROCK MB G41M-VS3 with latest BIOS – integrated sound – Nvidia 9600 GT PCIe – 4 GB RAM. All else seems to work but the sound – from Device Manager the sound drivers are indicated to be up to date – and DriverMax also indicates that all drivers are up to date. The sound works fine on the other systems on the same computer – Win XP x64, Win 7 x32 and Vista x32. Any ideas?