Open the HP USB Disk Storage Format Tool. Select your USB drive from the list of available drives. Select the FAT32 file system and click the "Start" button.
Click "Start" from the desktop and select "All Programs." Choose "Accessories" and select "Run." Type "%systemroot%" into the resulting box and press the "Enter" key. A new window will appear.
Click on "Tools" and select "Folder Options." Click the "View" tab and select the "Show Hidden Files and Folders" option. Click the "OK" button.
Select the files "boot.ini," "ntldr" and "ntdetect." Right-click these files and select "Send to." Click on the USB drive on the list of drives. Windows will copy the files onto the USB drive.
Download and install PEBuilder. The PEBuilder program has the ability to put a bootable copy of Windows XP on the USB drive.
Insert the Windows XP Install CD into the appropriate drive. Click the "Browse" button next to the "Source" field. Select the Windows XP install files from the CD.
Change the "Output" field to "BartPE." Click "Build" and the software will build a bootable Windows XP disk.
Click "Start" and select "All Programs." Choose "Accessories" and click "Run." Type "cmd.exe" in the box and press "Enter."
Insert the USB drive into the appropriate port. Type "cd\" and navigate to your root directory. Type "cd pebuilder#\plugin\peinst", replacing "#" with the version number of your PEBuilder installation.
Type "peinst" and press "Enter." A new window will open. Select option "1" in the menu to access the "Change source path" option. Type "c:\pebuilder#\BartPE", again replacing "#" with your PEBuilder version.
Select option "2" and press "Enter." Type the letter assigned to your USB drive, followed by ":", then press "Enter." Select option "5" and press "Enter." When the computer has completed the process, Windows XP will be installed onto your USB drive.
Copy the BIOS update files from your desktop to the USB drive. Remove the USB drive, and insert it into the original computer.
Restart the computer. Enter the BIOS boot menu by pressing "F2" during the BIOS start-up. Select the option to boot from USB drive, and press "Enter." The computer will boot from the USB drive, allowing you to run the BIOS update program.