My Kin Onem was recently showing an 'updating modem' error that Verizon and Sharp (the phone's manufacturer) didn't seem to know much about, beyond the usual replacement options that were not very helpful. Not knowing what else to do, I bought and activated a different phone. After activating my new phone, I decided to take another look at my Kin and, for some reason, I was able to fix it today, and the fix was actually pretty straightforward.
After plugging my Kin into my PC, I went to 'Devices and Printers' (in the Start menu) and clicked on my phone's icon, which was now just a white hard drive icon since it was unrecognizable. When I clicked on it, Windows noted that there was an error, and asked if I wanted to run Troubleshoot. When Troubleshoot ran its course, it asked whether I wanted to search for a replacement device driver (since that is apparently where the error originated). After it searched for a new driver, my computer automatically installed one on my Kin and the 'updating modem' error message disappeared! My Kin then restarted itself, and it was good as new . I was able to sync it with Zune and put everything I had assumed was irretrievably lost onto my computer.
I don't know whether the error will happen spontaneously again, but I am happy to have fixed it for now.