Thank you!!!
I followed these steps:
- remove battery and unplug power supply
- press and hold power on button for 30 seconds
- leave battery out but plug power supply back in
- press power on button and then tap on the f10 key immediately (a number of times) (I did have to hit escape here instead and get into BIOS, but this is specific model dependent I guess)
- the bios setup menu appears
- select reset defaults (load default values)
- select save and exit
Worked perfectly on my hp 431 laptop!