Create a CD-R with the BIOS file on it or USB flash disk with the BIOS file or both. Place the CD-R and the flash disk and restart your computer.
The BIOS file should be directly on the root of the CD-R or flash disk, not in a folder. The BIOS may be able to reach the BIOS file on the media and recover. He said the laptop took over 10 minutes to update the BIOS, and then it restarted and shutted down.
I downloaded the manual of the HP G62-208CA laptop.
It shows how to remove the RTC battery, but after I opened, I don't see the RTC battery at all.
Additionally, you can choose Operating System to see the drivers that will be compatible with your OS.