The Xbox 360, like many personal computers, uses something called a BIOS. Short for Basic Input/Output System, this is the first software a system runs when powered on and is an interface between the operating system and hardware. Because the BIOS is essential for the Xbox to work properly, it is important to understand how to change or repair it if the need arises. This is accomplished by flashing the on-board BIOS, which simply means replacing the current BIOS with one of your choice.
Find an Xbox 360 BIOS that fits your needs. There are many available free online (see Resources). Download the file and save it on your computer. This file will be important, so save it someplace you can easily locate it later (such as on the desktop).
Download Xbox modification software and install it on the computer. There are many
types available; be sure the one you download specifically lets you flash the Xbox
BIOS. XBTool (see Resources) works well.
Launch the Xbox modification software and load the Xbox BIOS you downloaded
in Step 1.
Save the file by clicking on "Save as," and name the file "Xbox." Save the file
on your computer in the same location as the Xbox BIOS file.
Switch on the Xbox and select the Network icon. Select the FTP program and launch it by pressing "X."
Choose the computer's hard drive in the left column of the FTP program (usually C drive). The drive's contents should be displayed on the right.
Choose the Xbox hard drive listed in the left column (again C drive) and the contents will be displayed on the right.
Drag the Xbox BIOS file you created from its location on the computer hard drive to the BIOS folder in the Xbox's hard drive. Wait as the FTP server transfers the file to the Xbox.
After the transfer is complete, turn off the Xbox and unplug all the cords. Remove the hard drive, located on the left side of the Xbox (or top if you have it set up vertically), by pressing the release button. Flip the Xbox upside down and place it on a table. Remove the stickers and rubber feet, revealing screws. Remove the screws using a Torx screwdriver.
Turn the Xbox over to its normal position, and remove the upper casing. Locate the DVD drive, a large metal box behind the place where you insert discs. Use the Phillips head screwdriver to remove the screws holding the DVD drive in place, as well as the two on the left side of the hard drive next to the DVD drive.
Lift out the DVD drive and detach the two cables running into it. Remove the cables that were running to the hard drive as well.
Remove the metal grill protecting the modification chip by releasing the tabs. Locate
and flip the two small switches on the modification chip into the "off" position.
Reassemble the Xbox and plug it in.
Turn on the Xbox and wait for the BIOS menu to appear. Select "Flash BIOS" from the menu. When prompted, select "Yes." The Xbox will install the new BIOS and then shut itself off. Turn on the Xbox and test the system by looking through the menus and running a game to confirm that everything is functioning properly. The BIOS is now updated.
Turning off the Xbox or losing power while flashing the BIOS can damage or ruin the system. Opening or modifying an Xbox 360 voids its warranty. If the new BIOS is not compatible with the modification chip, the system may not run properly. Make sure they are compatible beforehand.