some people are saying its a bios password. you might be able to reset your bios by removing the cmos battery for 10 minutes then putting it back on. make sure the pc is off and the power supply is unplugged from the wall as well.
cmos battery
i've never heard of a locked bios straight from manufacturer but it is possible for users to create one. perhaps search for your "your brand of pc password" on google to see if you get any hits.