I've just swapped over the hard drives on my families two xbox's (the wife had a 60GB and never used it while the boy had 20GB which was full up). I've gone to reconnect to the internet and the boy's xbox connects up fine, but no matter what I do, the wife's keeps saying there is an update and then inventing a MTU error.
I've followed the trouble shooting guides to try and get her xbox back online, but every time I test the XBL connection after resetting the modem etc it gets part way through the test and then warns that there is an update I must install. If I say no it disconnects from XBL, and if I say yes it creates the MTU error again.
What is error code 3143-0000-0080-0300-8007-2751, and how do I install the update without connecting XBL so I can get her back online.