Victor's HP All-in-One speakers quit working after he upgraded to Windows 10. Leo says that it could be a software issue, but it could also be that the cable that comes from the speaker itself may have become unseated. Leo says it's more likely that it's a driver issue, though. Victor should try Windows Key + X for the Device Manager and look into the settings for his audio driver and see if there's an X or a triangle with an exclamation mark to indicate a driver failure. Victor says it doesn't show his speakers at all and he can't install the drivers to get it going. If he can find them, he should delete them and let Windows reacquire them.
It also sounds like Windows doesn't think he has audio hardware at all. That means a faulty sound card or audio chip. Or it could be disabled in the BIOS. Victor should try rebooting the machine, get into BIOS with F10, F11, Escape, or the Delete key. That will get him into the BIOS and he can look to see if the audio has been disabled. He should also try pressing Windows Key, and typing "Troubleshoot" and he can get into the audio troubleshooter. The chatroom says that HP has a hardware diagnostics program that he can download and run.
Worst case scenario, he can reinstall Windows 10.