americabcd

I am currently using acer VN7-591G with GTX860m. The bios version is 1.13. I alrealdy had it unlocked to get advanced power options. I wanted to flash my vbios through nvflash but no luck at all. I kept getting the same message of "EPPROM Indentification failed'. So I tried flashing my bios rom with fpt and prr.exe on a DOS USB. After I entered 'cd fpt', then 'prr', then 'fpt -f xxxx.bin -bios', I kept getting the same message, "Error 28: Protected Range Registers are currently set by BIOS, preventing flash access. Please contact the target system BIOS vendor for an option to disable Protected Range Registers." Isn't Protected Range Registers already been disabled through ppr? If not, can I flash my bios in an alternative way? Or is there another way for me to flash my vbios? Thank you very much.