Since you guys are no longer making Xbox 360 consoles, what is the suggestion to do with an...

If she still has games for a 360, she can still play them on the console. 360 servers haven't been shut down yet. If you are wanting to get rid of it, you would have to see if there is anywhere around you that would give you money for it, but Microsoft doesn't have any kind of way of sending them back to them.

I do not want to know what it is but make sure your password is not longer then 16 characters I know the 360 consoles including the emulator do not like passwords longer then 16 characters. If it is longer then 16 characters you will want to change it
to something less then 16 characters.

What kind of xbox 360 console are you using? If that is the model with outer HDD I suggest you to make sure that the HDD is formatted and well connected to your console.

Are you sure that the IP of the Xbox 360 isn't changing? This would make the the DMZ not work any longer since it would be trying to put another IP that's unrelated to the Xbox into DMZ. This is likely to happen if you do not have a static IP setup for your
Xbox 360.

Hi there. Since the Xbox 360 console has already been modified, it can no longer be "un-modified" or rectified to it's original valid state officially. Since modifying an Xbox 360 is in violation of the Xbox LIVE Terms of Use and Code of Conduct, you are
not allowed to use Xbox LIVE services on the modified console, and may face consequences such as an account or console ban if you attempt to use any online features. You can either keep the console offline, forfeiting any online software updates or online
features, or you can get an un-modified console. I suggest that you attempt returning the console to the person that you bought it from or sell it to someone else (stating that it is modified), and buy a new or used (un-modified) Xbox 360 console.