I ran into the same probelm on my 8776c. Here is what I did. I checked the specs on your computer and the modem/audio is the same.
First, download the driver from the link below.
http://www.hp.com/cposupport/personal_computing/software/macnaw2k.exe.htmlSecond, open up "System" from the control panel. Click on the Hardware tab and then on the Device Manager button. Under "other devices" you should see a PCI Communications... with a question mark and exclamation point. Double click on it. Click on the Driver tab and then on update driver. Select next, then click search for a suitable driver for my device. Check the box next to specify a location then click next. It will ask you what the location is. Tell it C:\SoftK56_PCI_Modem_Driver\NT52013.inf. Then click ok.
That should do the trick. Restart your computer and you should be good to go.