Bios upgrade winphlash error -144: BIOS is not flashable with HP, Compaq, Presario, Pavillon

I know this notebook is from the stoneage. I found a Presario 2500 on the street (I live in Brussels, so it is quite common to find perfectly working stuff on the street) and out of fun I installed some stuff and also tried to do a BIOS update.

Winphlash gave me the message: -144 "BIOS is not flashable". I got my teeth into the problem which seemed to be related to the nonworking battery (especially reported by Dell Inspiron 1501 users). After sucessfully getting the battery to work again by freezing it I still got the same error-message.

It took me a couple of days to find out that actually my "Presario 2500" from the street is neither a Presario 2500 (as written on the display bezel and in BIOS), nor a Presario 2510EA as a label suggests at the back of the computer, but it is a Pavillon ze5200! This is what the chipset told the phlash utility it is.

To find out how the chipset identifies itself, you have to edit phlash.ini in the directory where winphlash.exe resides (most likely c:\swsetup\SPxxxx\)
change Advanced=0 to Advanced=1
change HideAll=1 to HideAll=0

so it looks like that:
[UI]
displayver=0
Advanced=1
EnableCmdLine=1
HideAll=0

save and close and start up winphlash again, click the advanced button, choose the DMI tab and in "Category" select "system". In the row "Product Id" you will see the modelnumber of "chip specified" (see picture below) in my case it was reading "Pavillon ze5200". I closed winphlash, downloaded the correct bios (the one for the Pavillon ze5200 which is K.13) and the BIOS update went perfeclty well without any problems.

this is closely related to:
http://forum.notebookreview.com/hp-compaq/17872-presario-2500-2505ea-bios-settings.html
but this thread is closed, so I can merely refer to it.