How do I unlock a BIOS password on Dell Precision M4500?

Chandra, not on this model. I'd try these first

w7cgsh9u

u3uk00ag

jjFqH198wFf4N7u6

455hq04f

there are a few fee-for-service online that will generator passwords for you. Cost is anywhere between $15 and $30. Now, you can most likely resolve this by downgrading your BIOS to A14 BIOS.For that you will have to download the older BIOS file from this site. Use the CMD command to get to the DOS terminal. There you creat an HDR file using the command "E6400A14.exe /writehdrfile" (without the quotes). Then copy the file E6400A14.HDR to a USB thumbdrive.

Remove the battery from your laptop and unplug the power cord. Plug the USB thumbdrive into your computers USB post. Hold down the "END" key while you plug the power cord in and release the "END: key when the battery LED light starts. If the battery LED light blinks red/blue your BIOS will be flashed you must wait until your laptop restarts. Now you have the A14 BIOS and 1F5A changes to 2A7B. With that you should be able to use an online passcode generator like this one. There are different approaches to this, if the one I formulated appears to convoluted, check on here for in-depth instructions.

You also want to consider to notify Dell and see if they can help you if you can somehow prove that this is your computer.

Again, this model does not reset the passcode by removing any batteries nor does it have a CMOS jumper. Those things have long gone by the wayside.