i have a hp compaq nc6000 running on xp pro. keep coming up with error message c000021a fatal system error so cant access windows. trying to access bios to boot from disc but coming up with admin password. tried removal of cmos battery cable but still asking for admin password. is there anyway to bypass the password or boot from disc without accessing the bios first ?

Have you physically removed the battery from the motherboard and left it out for at least 5 mins?

Are you talking about Window's Admin password or the motherboard's password. If its the motherboard password, by removing the jumper and the battery should remove the motherboard password and back to its factory default setting. But if it is a Window's Admin password than I am sorry I can't help you. Maybe someone else will.

Try to get hold of the motherboard's instruction manual--there should be a jumper that you can remove to erase the memory. The manual should provide a picture that will guide you to the correct jumper.

If windows admin password there are loads of pieces of freeware that will do it.. (google it)