how to bypass a used computers password

I'm going to assume that this is not the 'normal' log-in password when Windows boots up.

I assume that this is a BIOS level password that can be set to prevent unauthorized access to the PC.

If this is a laptop, you will need to take it to an authorized service shop to get the password reset.

They will require you to show proof of ownership.

For a desktop, you need to reset the password, CMOS RAM, or both.

If you can identify the manufacture of the system or the motherboard, you should be able to download a manual, or jumper setting instructions.

Set the jumper to clear, boot up, shut down.
Set the jumper back to normal.

If you cannot identify who made the PC / motherboard, then you can try pulling the CMOS battery and power cord for at least 30 minutes.

Put the battery back in, and power the PC up.

You should be able to access BIOS settings at boot.
You will need to reset the settings as needed.

If this PC has Windows NT on it, you cannot start an NT session without the proper password.

Chas

As what Chas has mentioned, you need to tell us whether it is a laptop or desktop pc?

For desktop - u will have to refer to the motherboard service manual to set the jumpers in order to clear the bios password.

For laptop - there is not possible way for you to access the jumpers. u will have to send in the unit to the service center or call in the hotline (whatever PC brand that is) to ask for assistance.
To curb theft prevention, you are required to submit a copy of your proof of purchase and maybe even your identification documents. before they would proceed for u.

Really need Make & Model, some laptops can be cleared relatively easily.(though only a few)

If a desktop - look on the underside of the cover - check for c-mos jumper (clear) if there is a diagram of the motherboard

Lots of good info on this problem at this url

http://www.pwcrack.com/security_chips_ibm.shtml

Good Luck Lee