How to Flash the BIOS or UEFI with a USB Flash Drive

Summary: Update your Dell BIOS using a USB drive when Windows won't boot. Quick F12 menu method for emergency BIOS flashing.

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Instructions

Important: This article covers one specific method for updating your BIOS using a USB drive. For complete guidance on all BIOS update methods and troubleshooting, visit our comprehensive BIOS and UEFI Update Guide, which includes detailed instructions for multiple update methods, compatibility checks, and advanced troubleshooting steps.

When to Use This Method

The BIOS or UEFI can be updated from the F12 boot menu, outside the operating system. This method is particularly useful when:

  • Your computer is not booting to the operating system
  • The BIOS .exe file fails to start the flashing process
  • You need to update without AC power (for supported systems)

Prerequisites

  • A USB flash drive
  • A computer connected to the Internet
  • Dell computer that supports F12 boot menu BIOS update

Note: Note: If your Dell computer does not support updating from the One Time Boot menu, learn to Create Bootable USB for Windows using Dell Diagnostic Deployment Package. For all other BIOS update methods, refer to our complete BIOS update guide. 

Step-by-Step Instructions

1. Download the BIOS File

  1. Browse to the Dell Drivers & Downloads page
  2. Identify your Dell computer using the Service Tag or Express Service Code
  3. Select your Operating System
  4. Under Category, select BIOS
  5. Locate the latest System BIOS
  6. Click Download and save the file to your computer

2. Prepare the USB Flash Drive

Format your USB drive based on its size:

For drives 32 GB or smaller:

  • Open File Explorer, right-click the flash drive, and select Format
  • Ensure the file system is set to FAT32

For drives larger than 32 GB:

  1. Open PowerShell with Administrator privileges
  2. Type: format /FS:FAT32 X: (replace X with your drive letter)
  3. Press Enter

3. Copy and Flash the BIOS

  1. Copy the downloaded BIOS update file to the formatted USB flash drive
  2. Plug the USB drive into the computer you want to update
  3. Restart the computer and tap F12 at the splash screen to enter the boot menu
  4. Under OTHER OPTIONS, select BIOS Flash Update
  5. On the update screen, highlight the BIOS file name using mouse or Tab key
  6. Click the file or press Enter to begin the update
  7. Monitor the progress shown on screen

Need More Help?

This method covers USB-based BIOS updates from the F12 menu. For comprehensive coverage of all BIOS update scenarios including:

Visit our complete BIOS and UEFI Update Guide for detailed information on all available methods.

Affected Products

Alienware, Dell All-in-One, Dell Pro All-in-One, Dell Pro Max Micro, Dell Pro Max Slim, Dell Pro Max Tower, Dell Pro Micro, Dell Pro Slim, Dell Pro Tower, Dell Slim, Dell Tower, Inspiron, OptiPlex, Vostro, XPS, G Series, G Series, Alienware , Dell Laptops, Dell Plus, Dell Pro, Dell Pro Max, Dell Pro Plus, Dell Pro Premium, Inspiron, Latitude, Dell Pro Rugged, Vostro, XPS, Fixed Workstations, Mobile Workstations, Dell Pro Max Micro XE FCM2250, Inspiron 5000, Inspiron 5000e, Inspiron 700M, Inspiron 710M ...
Article Properties
Article Number: 000123870
Article Type: How To
Last Modified: 01 Sept 2025
Version:  18
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