I have similiar Problem.
I have Compaq Presario F700
It came with Vista and now I changed to WinXP Pro Sp2.
All Other drivers I search and got from different sites.
only Audio is not working.
I searched HP pages, but it says that there will be a problem of Audio when O/S changes.
If anybody can help me with this.
Chipset is Nvidia nforce560
Audio device is MCP67 High Defenition Audio.
Regards,
Abu Nuha