If you own an Xbox 360, try this at home:
1. Sign into your Windows Live! Account.
2. Go to service.xbox.com. You should see something like this:
3. Click “Register a New Device” and enter your serial number. If you’re me, you’ll see something like this:4. Repeat step #3 four or five thousand times, confirming each time that yes, you correctly entered the serial number every time.
5. Call 1-800-4MY-XBOX. Five times. Have the same conversation with five different people.
CUSTOMER: “I can’t add my device to my registered devices at service.xbox.com.”
1-800-4MY-XBOX: “What is the serial number of the device?”
1-800-4MY-XBOX: “That device is already registered to you.”
CUSTOMER: “Not at service.xbox.com it isn’t.”
1-800-4MY-XBOX: “Well, what is it that you wanted to know about the device?”
CUSTOMER: “Why I can’t register it at service.xbox.com.”
1-800-4MY-XBOX: “I can’t help you with that.”
CUSTOMER: “Sort of twisted that the error page tells me to call you, don't you think?”
6. Find KB article 931129, which appears to address the issue and advises the customer to “Click Associate a device you registered on the phone with your Windows Live ID.”
7. Look at the photos in steps 2 and 3 above. Locate the “Associate a device you registered on the phone with your Windows Live ID” option. [SPOILER ALERT! It does not exist. There is no "Associate a device you registered on the phone with your Windows Live ID" option.]
Your obedient servant,