Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

My neighbor has asked me help with his laptop, an HP with lost power-on password. I tried inserting an Ubuntu cd to format the partition, but well... it doesn't even get there. Any ideas?

share|improve this question
HP consumer grade laptops can be cleared by removing the cmos battery, Business grade laptops cannot, the password is stored on a separate chip from the bios chip and cannot be erased by removing the cmos battery. Post your exact model for further instructions. – Moab Feb 27 '11 at 20:54
up vote 1 down vote accepted

As MaQleod said - wiping the BIOS settings is the only way to go.

A few notes though:

Laptops often don't have a battery specifically for the BIOS but often either draw power from the main battery or use an EEPROM (flash memory) that needs no battery.

You can sometimes wipe the BIOS by removing the laptop battery and leaving the laptop unplugged for an extended period (I'm talking weeks here), but if the laptop's using flash memory that won't work.

The only other option is to locate a set of CMOS Clear jumpers / solder pads on the motherboard and join those together with a screwdriver / wire to try and wipe the BIOS. Finding it could be hard though.

share|improve this answer
Every laptop I have ever worked on has a CMOS battery, not always easy to get to, depends on the make and model. – Moab Feb 27 '11 at 20:51

I assume you mean bios password. In this case you will need to open up the laptop and pull the bios battery from the motherboard, usually a few minutes out will be fine to erase the bios and default it back to factory. Put the battery back in and you are good to go.

share|improve this answer

It's also POSSIBLE that you can reset the password by flashing the BIOS according to HPs procedure for your make & model.

I'd try this only as a last result, as it's generally recommended to remove a bios password before flashing, so this may render your system inaccessible or do something otherwise funky to your BIOS. I just thought I'd throw it out there in case all else fails.

share|improve this answer
It's unlikely you'd be able to get to a stage in the boot process where flashing the bios is a possibility. Boot passwords generally stop you doing anything at all on the system. – Majenko Feb 27 '11 at 19:05
I saw more than one mention of this possibility specifically in regard to HP laptops, so I thought there may be something particular about the HP flash utilities. /shrug – Kara Marfia Feb 27 '11 at 19:16

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.