Hello kaaate,
Welcome to the HP Forums! I hope you enjoy your experience!
I understand the sound card on your computer is not working. To assist you properly, I do require the following information:
1. The computer's model number. If you require assistance locating this information, please reference this website: Locating the Model Number of the Computer
2. The computer's operating system. If you require assistance locating this information, please reference this website to determine your Windows operating system.
3. Have you installed any new hardware on this computer, before the issue appeared?
4. Have you installed any new software or drivers on this computer, before the issue appeared?
Thank you for choosing the HP Forums. Have a great day!
Mario