Current problem xbox live is having. Microsoft is currently looking into the issue. Issues like this usually don't last very long so I'm sure you will be able to get back to gaming soon.
support.xbox.com/.../xbox-live-status Right from the status page
XBOX LIVE Service
Users may experience difficulties with the following services:
Signing in to Xbox LIVE
Affecting the following LIVE Platforms:
Games for Windows LIVE
Xbox 360 Console
Zune PC Client
1/29/2013 5:51:38 PM PST:
You might have been kicked off of Xbox LIVE and you might be having some problems logging back in. We are investigating this issue and we’ll get this fixed ASAP so you can get back to your favorite games, apps, movies, and music. We will let you know how
things are going in 30 minutes. We appreciate your patience."
Did this solve your problem?
Sorry this didn't help.
Great! Thanks for marking this as the answer.
How satisfied are you with this reply?
Thanks for your feedback, it helps us improve the site.