Ok, gonna try to be a little more clear on this.
You need to provide all information about the system and the specs of the system. If you don't know the specifications, can you at least provide a model number of the HP you've got?
Meanwhile, check this things:
1. Are the speakers plugged in to the correct jack on the sound card?
2. Are the speakers powered (have an AC adapter)? Are they plugged in properly?
3. Have you tried testing the speakers with another device/computer?
4. Have you checked the device manager to see if the hardware is working properly?