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- How Unlock the BIOS
June 20, 2013, 11:20 am
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The BIOS is said to be locked and needs a password to unlock it.
I need to change the BIOS to get it going.
Is there any way I can bypass or otherwise undo the lock?
A program or some such?
I have tried removing and replacing the MOBO battery.
Re: How Unlock the BIOS
Norm X wrote:
On non-business motherboards, they store two passwords in CMOS RAM.
That's why, removing the CMOS battery, or using the "Clear CMOS"
jumper (with the computer unplugged!), works so well.
For things like business laptops, the passwords are stored in a
2KB EEPROM. That is separate from the BIOS chip. Removing all power,
doesn't change a thing on those.
In neither case, will programming the BIOS chip, clear the password.
The flash cells in the BIOS chip, are unrelated to the CMOS RAM in
In the first case, the Clear CMOS jumper will do the job.
In the second case, the instruction manual tells you to
"send it back to the factory", while a guy in Eastern Europe
used to sell a solution for $50. (It consisted of a USB
to TTL serial cable and software to reprogram the 2KB chip.)
The implication being, if you know how to program one of those
tiny serial EEPROMs, you could fix it.
So in the business laptop/computer case, the only person
inconvenienced, is the computer owner. Whereas every thief
will have the tools to reprogram the 2KB chip :-)
There could be more mechanisms than that, but that's what I've run
into so far.
On a laptop, you would not rely on that password scheme, to protect
the content. If you travel on business, you'd want full disk encryption,
to protect the disk (i.e. when the border people copy the hard drive :-) ).
Some laptops have hardware support for full disk encryption (hard drive
supports it), and so that's another password to remember.