The bad news is all lights being on your iTwo indicates a firmware corruption issue.
The good news there's an easy fix.
If you have not already downloaded and installed UC from your products download page, you need only to do so -
http://www.presonus.com/products/AudioBox-iTwo-Studio/downloads
Once you've installed the latest supported version of UC (which is v1.8.1 at present), open it up and it should see your AudioBox. It will request a firmware update. Go ahead and execute the update. This should fix your issue.