There is no official support from HP since they never shipped this machine with Windows 7 installed. Now lets find out something about the sound chip (since you failed to identify the sound chip).
Open Device Manager, find and double-click the sound device, click the Details tab, select "hardware id" and give me the hardware id string that begins with "PCI\VEN" or "HDAUDIO", (1st./top line of text only).
Generic drivers will fail install on a laptop. Laptops require specific drivers from the laptop maker.