Here’s a .pdf by Fastback68 which appears to to compiled from qasimtoep’s old website explaining how to reset a Dell BIOS password using a paperclip.The laptop that was used in this demonstration is a Model 630 type PPX.
There are a lot of people who have a dell or similar laptop that they are not able to use because of a special password chip that can’t be cleared by resetting the CMOS using software or by removing the battery. The chip that Dell uses is called a 24C02 chip. Dell will not give any help to these people without verifying that they are the original and registered owners of these laptops. Their justification is that it is part of their security / anti-theft program, and keeps people from stealing their laptops or accessing their data.
Included in the .zip file with the .pdf are instructions that show you step by step instructions on how to reset the chip by using a paperclip and how to remove a laptop bios battery for Dell computers that support the resetting of passwords using that method (Latitude L400 is used)
Programs to create a bootable thumbdrive,CD or floppy to remove the Dell Service Tag Number from the bios.
Also as an added bonus a simple vbs script that shows you your Dell Service Tag Number while in Windows
on error resume next
strComputer=InputBox ("Enter the computer name of the server you'd like to query for Service Tag")
Set objWMIservice = GetObject("winmgmts:\\" & strComputer & "\root\cimv2")
set colitems = objWMIservice.ExecQuery("Select * from Win32_BIOS",,48)
For each objitem in colitems
Wscript.echo "Dell Service Tag: " & objitem.serialnumber
also this site has a good tutorial http://www.weeklygripe.co.uk/a709.asp