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PC Hacks
book

PC Hacks

by Jim Aspinwall
October 2004
Intermediate to advanced content levelIntermediate to advanced
304 pages
7h 44m
English
O'Reilly Media, Inc.
Content preview from PC Hacks

Hack #2. Bypass the BIOS Password

Recover from a CMOS memory-affecting virus or work around a boot-time password by making BIOS forget all it once knew.

A PC goes through a process when it is first turned on: the Power-On Self-Test, or P.O.S.T. Some system boards provide security measures [Hack#1] that demand a password before beginning the P.O.S.T. process or allowing you into the BIOS setup program.

The original IBM-PC (1981) did not provide any security measures or a BIOS setup program; all it had was a P.O.S.T. If you needed to configure a PC, you did it with switches and jumpers. A program to set up the system BIOS and configuration did not come along until the IBM-PC/AT (1984), and it had to be run from a special boot-up diskette. The idea of providing a user interface and access to the system configuration settings within the BIOS did not come along until about 1986. Today no PC system is made without this valuable built-in setup feature. Eventually, the security feature of password-protecting access to the system came along.

If, after turning on your PC, you are prompted for a password instead of greeted with a fancy logo screen or the technical gibberish that suggests the system is getting ready to let you use it, then a security feature has been turned on that we call a " pre-boot password." Without the right password to get past this point, the system is basically dead in the water—game over, do not pass go and collect $200—unless or until you reset the BIOS setting. ...

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Publisher Resources

ISBN: 0596007485Errata Page