So I think I'm having the same issue a lot of people are having, but I think mine may be a bit different.
First off I have an XBOX360 Slim 250GB connected wirelessly.
I hadn't played my XBOX in about 4 or 5 days. Then yesterday I hopped on to play with some friends. I get the message that there's an update for XBOX live.. So I start downloading it. Barely 10% of the way through the download it stalls. It tries to continue downloading 3 times then gives me a long error code (I forgot to write it down, but it was practically identical to some that I saw other people getting on here). Up until the update it was working perfectly fine and I had absolutely no issues with it whatsoever.
But the bit that (I think?) is different me is; whenever I test my connection it sometimes fails trying to connect to the network, other times it finds the network but not the internet, others it gets the internet but not XBOX live, and as I'll mention soon; rarely it connects to XBOX live fully. I think if I could get it to connect to XBOX Live I might have a chance at it completing the update through some miracle? But for now it won't prompt me to update because it cannot connect to live.
What I've tried:
- Turning our modem on and off again several times (By unplugging or by the button). OCCASIONALLY this causes it to ask me to update again and when I hit yes it gets to different stages of the update before stalling.
- Restoring to network factory defaults.
- Clearing the cache.
I know there's some USB method, but I lack a USB and I'm not sure how my MAC would deal with the files when I download them.
Oh and a final note is that we have another XBOX connected to our network which downloaded the update perfectly fine and hasn't had any issues.