Press and hold the F, G, and H keys together at the same time. You should hear a beep. Is it the same beep you’re complaining about?
To turn it off:
Right click My Computer
View button at the top
Show Hidden Devices
Non-Plug and Play Drivers
Right Click “Beep” and hit “Disable.”
Restart your computer, and it should go away. Try the FGH thing again.