How do I reset a system passowrd?

Some one set a system password on my laptop.

How do I clear this

I pulled the CMOS batter and still getting it.

Please assist if possible as my computer will not boot

crwdns2934089:0crwdne2934089:0 crwdns2934093:0crwdne2934093:0

crwdns2934109:0crwdne2934109:0

crwdns2889612:0crwdne2889612:0 0
crwdns2934285:0crwdne2934285:0