OK this I've been having this problem the last few days and nothing seems to fix it. Every time I turn on my Xbox my Internet disconnects and when it finally connects it disconnects immediately after than when I turn off my Xbox my internet connection comes back. I've heard things from I need a dsl filter to my MTU is to low. When I run the Xbox connection test I get to the internet portion and it always fails. I have a wired connection and I've tried everything from getting a static IP to formatting my hard drive. I've tried everything imaginable and nothing has even made any progress.