HP fucking sucks like that. If you go the route of trying to flash the VBIOS, note that it's quite risky if you don't know what your doing. For instance, a power failure during the actual update could brick the system permanently. Just be cautious. I'd reccomend using the UNETBOOTIN software to make the bootable ODS USB drive (just choose the "distribution" FreeDOS, which is MSDOS compatible). Then, after you have a bootable USB stick, put the VBIOS file on it. Then boot to the USB stick and run the VBIOS update file (write down the name somewhere)
UNETBOOTIN is here:
http://unetbootin.sourceforge.net/
Hasn't been updated for a long time, but it works and it's free.