Word – Removing CMOS battery doesn’t reset BIOS password


I have an old acer extensa 4620Z which I just disassembled, removed the CMOS battery and reassembled and it's still asking for a password.

One thing I read is that you should leave it for 10 to 15 minutes, I left it for a 3 – 4 minutes, can this actually make a difference, if it has no battery, then should it matter if it's 10 seconds or an hour? Does this have any merit?

Other than that, I'm stuck, what can I do about the BIOS password?

Best Answer

I've read anywhere from 30 secs to 25 minutes (even one site said a few days) to wait after removing the CMOS battery. I've also read that some laptops have a "hidden IC which stores the password" or that the password may be stored on a sector of the hard drive. You might remove the hard drive and see what happens.

This site http://www.biosflash.com/e/bios-cmos-reset.htm has pretty good coverage of what can be done to reset the BIOS.

You also may be able to calculate the backdoor password for your particular model though I didn't see anything from a quick search.

And you can always try contacting the manufacturer via there support site but you may need some way of proving ownership.