1. Home
  2. Wi-Fi and Bluetooth Troubleshooting
  3. How to Discharge Your Machine to Reset Your CMOS
  1. Home
  2. Ethernet Troubleshooting
  3. How to Discharge Your Machine to Reset Your CMOS
  1. Home
  2. Guides
  3. How to Discharge Your Machine to Reset Your CMOS

How to Discharge Your Machine to Reset Your CMOS

This guide will cover how to discharge your machine to reset your CMOS, forcing your computer to re-enumerate its devices. This is useful for when a device, such as a Wi-Fi adapter, has vanished from Device Manager, and you have taken steps to correct the problem, such as updating the machine’s BIOS or reseating the device, but the device has not reappeared in Device Manager.

Please note that some machines have a CMOS reset button or procedure. This is often easier to complete than discharging the computer, so that may be worth investigating. Desktop motherboards may have a CMOS reset button, and laptops may have a keypress combination. This will vary by manufacturer and model.

Also, please note that any time you open up your machine, you do so at your own risk. This isn’t generally a dangerous or difficult thing, depending on your capabilities.

Discharging a Desktop  

  1. Shut down the computer by clicking Start > Power > Shut Down.
  2. Unplug the machine from the power outlet.
  3. Open the machine and remove the CMOS battery.
    1. This may or may not be necessary. You may want to try this guide without removing the CMOS battery first to see if this will be required for your motherboard, then repeat the process if it does not work, removing the CMOS battery the second time around.
    2. The CMOS battery is a large button battery, usually a battery number 2032. Click here for a plethora of images. There will be a metal clip over it, which you will want to push in with a screwdriver, which will usually cause the battery to pop up a bit, allowing you to remove it by hand.
  4. Press and hold the power button for ten seconds to fully discharge the machine. Then release the power button, then do it again, to be sure.
  5. Replace the CMOS battery if removed. The positive side will face outward, and the battery should snap right into place and stay there.
  6. Plug the computer back into the electricity.
  7. Power the computer on. You may see an error about CMOS values being reset. If you have never messed with these, press whatever combination sets things to default so that it will load into Windows. If you used custom BIOS settings, you might wish to set those back up.
  8. Once the computer is back up, right-click Start, click Device Manager, and check to see if the CMOS reset brought the missing device back.

Discharging a Laptop

  1. Shut down the computer by clicking Start > Power > Shut Down.
  2. Unplug the machine from the power outlet.
  3. Remove battery power from the machine.
    1. If the machine has an accessible, easily removable battery, remove it.
    2. If the machine does not have an accessible, easily removable battery, then you have two options.
      1. Open up the machine enough to disconnect the battery. You will need to refer to a guide or teardown manual for your specific model of computer.
      2. Run the battery down to empty through usage. This option is the hardest on the battery. Make sure that you completely drain the battery and that it will not power on.
  4. Press and hold the power button for ten seconds to completely discharge the machine. Then release the power button, then do it again, to be sure.
  5. Replace or reconnect the battery.
  6. Plug the machine into the electricity.
  7. Power the computer on. You may see an error about CMOS values being reset. If you have never messed with these, press whatever combination sets things to default so that it will load into Windows. If you used custom BIOS settings, you might wish to set those back up. If you had to run the machine until it was out of power, it might take a lot longer than usual to boot. This is normal, and will only happen this first boot after power is restored.
  8. Once the computer is back up, right-click Start, click Device Manager, and check to see if the CMOS reset brought the missing device back.
Updated on February 21, 2019

Was this article helpful?

Related Articles

Need Support?
Can’t find the answer you’re looking for? Don’t worry we’re here to help!
CONTACT SUPPORT