Reset the CMOS password isn't working!

I have an old Asus Z7100VP badged as an Evesham Micros WO 01151861 laptop (they've now closed down). I've set a passport a good few years ago but can't remember it ! Its definitely not Windows password as when I turn it on the Award motif briefly flashes on-screen.

I've tried removing the battery and removing and putting a pin cover different but to no avail ! However I may of done it wrong. So if someone could please help me !