Instructions
Navigate to the Xbox Online Service Center website (see Resources).
Click "Start a Repair Request."
Enter your email address and password associated with your Xbox account. Click "Log In."
Click "Request a Repair."
Select "Console Displays E74 Error" in the drop-down box. Click "Continue."
Enter your console's serial number if it is not already on file to determine your warranty information. If your console is under warranty, repairs will be free. If not, the cost of repair is $99.99. Click "Continue."
Enter your address in the fields provided. Click "Continue."
Select a shipping option. You can either print the prepaid UPS label yourself, or Microsoft will mail one to you. Click "Continue."
Enter your payment information if the console is not under warranty. Click "Continue."
Review all the information. If everything is correct, click "Finish."
Print the shipping label that appears on the screen if you selected that option. If not, the shipping label will arrive in one week.
Package your 360 in a box making sure the box is well padded and the 360 is secure. Mail your Xbox 360 to the address provided on the label, and in two to three weeks your repaired 360 will be mailed back to you.