I solved this same problem on a HP XP Laptopo computer three weeks with info from a link suggested by "Warlock".
This Pavilion a6167c will not update using the same procedure as before. The computer is running fine now, after reformatting and going back to factory original condition. I was still having some start and freeze problems after reloading, but everything cleared up after changing the CMOS battery. The problem now is I can't update Windows. This is preventing me from going forward with a few things.
I got an error message 8007F8F re time sync. The time is set and looks O.K. Where do I go from here with these updates. Can the BIOS c lock be off because of the battery change? How do I check or reset this?