@brabijo
Which “other” BIOS do you mean? And which BIOSes cannot be opened (by which tool)?
Please re-read carefully my guide.
EDIT 1: It is not my fault, that you are unsatisfied. A BIOS modification is not as easy as playing cards and flashing a wrongly modded BIOS may brick your mainboard. If you strictly follow my guide, you will succeed, but you should stay patient.
Yes, before you flash it, you should give the modded BIOS the exactly same name as the original one had.
EDIT 2: If you don’t know how to flash a modded ASRock Aptio IV BIOS, please read the related chapter within the start post of >this< thread.