The BIOS update failed
Why does my laptop say 'BIOS update failed'?
Written by The CommonFixes team · fact checked by CommonFixes review desk
Last updated
Short answer
A BIOS update writes new firmware to a chip on the motherboard, and it will refuse or abort if anything looks unsafe. The usual reasons are the battery being too low or the charger unplugged part way, the wrong file for your exact model, security features such as BitLocker or Secure Boot getting in the way, an antivirus or background tool interrupting the writer, or the flash simply being cancelled by a power cut. The good news is that a refused update is far more common than a broken one, and most laptops now keep a backup copy of the firmware to fall back on. The quickest thing to try first: check the machine still starts before doing anything else — If it boots into Windows, nothing is broken and the update was refused rather than half written. Take a breath and work through the causes below. If it will not start at all, go straight to the recovery step near the end. Most people are done in about 40 minutes.
Full walkthrough below: 7 steps for Windows, rated careful.
Sounds like this
- •A message appears saying the BIOS update did not complete
- •The machine restarts several times or sits on a black screen after the attempt
- •It boots but keeps offering the same update again
Why it happens
A BIOS update writes new firmware to a chip on the motherboard, and it will refuse or abort if anything looks unsafe. The usual reasons are the battery being too low or the charger unplugged part way, the wrong file for your exact model, security features such as BitLocker or Secure Boot getting in the way, an antivirus or background tool interrupting the writer, or the flash simply being cancelled by a power cut. The good news is that a refused update is far more common than a broken one, and most laptops now keep a backup copy of the firmware to fall back on.
Work through these in order
0% done- 1
Check the machine still starts before doing anything else
If it boots into Windows, nothing is broken and the update was refused rather than half written. Take a breath and work through the causes below. If it will not start at all, go straight to the recovery step near the end.
- 2
Charge it properly and keep it plugged in
Most makers refuse to flash below 30 or 50 percent battery. Charge to at least 60 percent, leave the charger connected, and do not close the lid or let it sleep during the update. Turn off any sleep timer first under Settings, System, Power and battery.
- 3
Make sure you have the exact right file
Get the update only from the maker's own support page, entered by your service tag or serial number rather than by a model name that covers several variants. The wrong file for a near identical model is one of the top reasons a flash aborts. Better still, use Dell Command Update, HP Support Assistant, Lenovo Vantage or MyAsus, which pick the file for you.
- 4
Suspend BitLocker before you try again
Open Settings, Privacy and security, Device encryption, or search for Manage BitLocker, and choose Suspend protection. A firmware change alters the measurements BitLocker checks, so without suspending it the update can be blocked, or you are asked for a recovery key afterwards. Find and save that recovery key from your Microsoft account first either way.
- 5
Turn off antivirus and close everything
Pause third party antivirus, close every program including the ones in the system tray, and disconnect docks, external drives and monitors. Then run the update as administrator and leave the laptop completely alone until it finishes and restarts on its own, which can take several minutes with a black screen in the middle. Never press the power button during that.
- 6
Recover a machine that will not start
Most modern laptops have a recovery mode. On Dell, hold Control, Escape and the power button with a USB stick containing the renamed BIOS file. On HP, hold Windows and B, then press power. On Lenovo, hold Windows and R with the power button. Check your maker's crisis recovery instructions for the exact key combination and file name, because they differ. This reads a clean copy of the firmware from a USB stick and rescues most failed flashes.
- 7
Clear the settings if it boots but behaves oddly
Enter the BIOS with F2 or Delete and choose Load Setup Defaults or Restore Defaults, then save and exit. A part written update can leave odd settings behind, and resetting them clears strange behaviour without another flash.
If none of that worked
If the recovery procedure does not bring it back, stop there. A truly bricked firmware chip needs reprogramming with a hardware clip, which is a workshop job and often covered under warranty. Only update the BIOS when you have a real reason to, such as a fix for a fault you actually have, rather than for the sake of being current.
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Who wrote this and how we checked it
The CommonFixes team
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We are a small group of people who spend our days repairing laptops and desktops for family, friends and small offices. Every guide here starts with a problem someone actually brought to us, and we only write down the steps that put the machine right.
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CommonFixes review desk
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Before a guide goes live, a second person walks through it on a real machine and checks each instruction against the maker's own support pages. Anything we cannot confirm is removed rather than guessed at.
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This guide was last updated on 10 August 2026. If a step no longer matches what you see on screen, tell us on the contact page and we will test it again.
A gentle reminder: back up anything you cannot afford to lose before major repairs. If a step ever feels risky, stop and ask a technician. There is no shame in that.