Problem flash 9800 gtx bios

I try to flash the bios as stated in the title!
I reboot on my usb key launches nvflash5.72

I type:
nvflash -4 -5 -6 9800 oc.rom
enter:

he said: supported EEPROM not found

Problem flash 9800 gtx bios

Try the nVFlash 5.57

"I reboot my key.
I type: dir; enter, to see what's inside
I type: nvflash -4 -5 -6 9800oc.rom, enter

pending or is there a way to change the voltage of my cg in RivaTuner or another? (vmode excluded of course)
because I'm mounting a 800/1200/2000 and after I am no longer stable and I still have the margin in temperature I am a full 72 degrees.

Are you sure the card sits correctly in the AGP slot? Take it out and look if maybe dirt or something is blocking contact in the slot. You have the power connector plugged in?