How can I get past password in the bios when booting up?

I have a thift store Dell Dimension XP Home Edition that worked excellent for six months but for some reason now is asking for a password during the boot up. This is before it gets to the windows stage. I asked about the previous owner at the thrift store but they have no idea who donated the computer so I have no way of asking the previous owner.|||Hi you can try to pullout the internal battery in side the motherboard for a five min. max . and try again to operate your dell it will ask you to enter a new date and time setting .. and erase the old password for yr Bios|||I agree with Thamer - have done this myself but had to re-load windows after would.|||if u knw wat cmos batery (the white silver colour coin like thing near ur processor..in ur mother board)then tek it out....wait for few minutes...then put it bak..jus restart ur system....u wil hav no password

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