"AC'97" is not a chip number nor a sound controller model number, it's merely a protocol. All sound chips made between 1997 and 2007 are "AC'97" compliant. All sound chipsets made since then are "HD" compliant, replacing "AC'97".
You need to include a valid chipset brand and number along with your computer/motherboard brand and model.
Also, 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", (1st./top line of text only).