Open Device Manager by swiping in from the right edge of the screen, tapping Search (or if you're using a mouse, pointing to the lower-right corner of the screen, moving the mouse pointer up, and then clicking Search), entering Device Manager in the search box, and then tapping or clicking Device Manager. You might be asked for an admin password or to confirm your choice.
Double-tap or double-click Sound, video and game controllers to expand that category. If a sound card is listed, you have one installed. If no sound card is listed, check the info that came with your PC to see if there's supposed to be a sound card installed. If there should be a sound card installed, you'll need to install one according to the manufacturer's instructions