I have been searching all morning into the afternoon. I had to set a bios password to keep my son off my Dell latitude d600 and saw that you can help via pm. If you are still active on here can you please help me too :-)
the usual method is to remove all power to the computer, pull it apart and find a little battery - like one in the back of a watch. pull it out for ten minutes, reassemble, and the CMOS password is wiped.
Depending on the laptop, there may be a jumper switch you can cross under some panel somewhere under the laptop. you cross it, reboot, and it resets the BIOS.
Although some do say that Dell has made these features obsolete.
I did see this though:
Undocumented BIOS feature of Dell Latitude D600
If you are only looking for the BIOS feature: Alt+E, Alt+F will reset your BIOS of your Dell Latitude D600 laptop to factory settings. It might work for other types as well. There you have it. No need to read on, unless you want to know how inefficient Dell works.
There is nothing to indicate when these were pressed - whether during boot, or at the password screen, or whether a reboot ras required after, no more information that what I have given you here.