How to restore sound

I downloaded and installed a trial copy of Leawo music recorder. After installation a prompt box advised that if the system sound was off I need to reset it. The sounds are indeed off. I immediately uninstalled Leawo and rebooted. Still no sound. Checked HP diagnostics on reboot and audio worked fine, but still not on the booted system. Tried system restore, which stuck for 20 minutes until I gave up. I went to mmsys.cpl (sound) which showed nothing unusual. How can I turn the sound back on?

Here's what I did: started system restore from boot and took a long lunch break. 2 hr later the restore worked. Sound back. But some other settings lost. So I need to schedule restore backups at least every 2 days.

I had, until my last computer crashed, a program that provided a user interface for sys restore. It's the only one I didn't back up, it just fell through the cracks, and now I can't remember the name. If you have a clue please let me know.

How come you have to make frequent system restores?
The software that caused the problem was uninstalled.
What happens after each restore?
The sound was restored?
What is not working that restores are needed?

Open device manager > click view > show hidden devices > look for any item that displays a yellow triangle with a black exclamation mark or any unknown device. If you see either one please post an image into the thread.

For many HP computers reinstalling the high definition audio CODEC fixes the sound.
On the HP website enter the computers serial or product number and operating and download a fresh copy of the audio drivers.
HP Software and Driver Downloads for HP Printers, Laptops, Desktops and More | HP® Customer Support

If the codec is not seen for windows 10 see if it is available for windows 7 or 8.
And if the IDT High Definition Audio CODEC is applicable to the computer's configuration please post that information into the thread.
Then if you lose sound again see what happens with a fresh install of the CODEC.