Hello Eclipsed,
I see that you are having sound problems on your HP computer as well. I have a couple of suggestions that may help with this issue.
I would first suggest trying a system restore to an earlier point when the sound was working. Here is a link that shows how to do a system restore on Windows 8.
If there are no restore points or this doesn't help I would suggest uninstalling the sound drivers in the device manager and restarting the computer.