How to clear an unknown BIOS or CMOS password.
Question
How to clear an unknown BIOS or CMOS password.
Answer
The below steps are
for a desktop computer and do not include steps on how to
clear a laptop CMOS password.
If you encounter a password prompt at boot or the BIOS / CMOS setup is locked as shown below and you do not know the password you will need to clear the BIOS password using the suggestions listed below.
Clear using jumper (recommended)
When inside the computer be sure you're
aware of the potential damage that can be caused by ESD.
On the computer
motherboard locate the BIOS clear / password
jumper or dipswitch and change its position.
This jumper is often labeled CLEAR, CLEAR CMOS, JCMOS1, CLR, CLRPWD, PASSWD, PASSWORD,
PSWD or PWD as shown in the picture to the right. To change the jumper
remove it from the two pins its currently on so that it covers the pin that is
not covered. For example, in the picture to the right pins 1 and 2 are covered,
you'd remove the jumper and put it on pins 2 and 3.
Once this jumper has been changed, turn on the computer and the password should be cleared. Once cleared, turn the computer off and return the jumper or dipswitch to its original position.
The location of the jumpers or dipswitches are dependent on the manufacturer of the computer and motherboard. However, below are some general ideas on where to find it. Remember that most motherboards could have dozens of different jumpers, make sure you're changing the CMOS jumper and not something else. If these general suggestions do not help refer to your motherboard / computer documentation or skip to the next step.
- On the edge of the motherboard - Most jumpers are located on the side of the motherboard for easy accessibility, verify by looking at all visible edges of the motherboard.
- By the CMOS battery - Some manufactures will place the jumper to clear the CMOS / BIOS password by the actual CMOS battery.
- By the processor - Some manufactures will place the jumpers by the processor of the computer.
- Under the keyboard or bottom of laptop - If you are working on a laptop computer the location of the dipswitch (almost never a jumper) can be under the keyboard or on the bottom of the laptop in a compartment such as the memory compartment.
- Other visible location - While it is possible that the jumpers / dipswitches may not be in a visible location, most manufactures try to make things easier by placing the jumpers / dipswitches in another visible location.
Generic passwords
Try using generic CMOS passwords. Note: many of these generic passwords are no longer used or only used with older computers.
Use a BIOS password utility
There are utilities designed to help bypass CMOS passwords. An example of a great utility to decrypt / bypass BIOS passwords is the PC BIOS Security and Maintenance toolkit.
Remove CMOS battery
Removing
the CMOS battery like the one shown in the picture to the right will cause the
system to loose all CMOS settings including the password. To do this locate and remove the
CMOS battery on the motherboard
for at least five-minutes. After this has been done put the battery back into
the computer and turn it back on.
Jump the CMOS solder beads
Older computers and especially older laptops don't have jumpers or dipswitches and require the user to jump a pair of solder beads on a circuit board. The identification and location of these solder beads can vary and if not available in computer documentation is only obtainable through the computer manufacturer.
If you've identified the solder beads they can be jumped by placing a flat-head screwdriver over the two beads and leaving it on those beads while turning on the computer. Once the computer has booted turn off the computer and then remove the screwdriver.
Contact manufacturer
If the above solutions do not help or you are unable to locate the jumpers or solder beads, it's recommended you contact the computer manufacturer or motherboard manufacturer for the steps on clearing the computer password.
Additional information
- See the CMOS definition for related links and information.