You can also try using NI's Measurement & Automation (MAX) tool to do the reformatting. MAX gets a shortcut on your desktop when you installed the FRC LabVIEW or you can find it under Start -> Programs -> National Instruments.
In MAX on the left it hopefully will list your cRIO and let you reformat or change the IP address.
Here are directions I just looked for and found on the ni.com/First KnowledgeBase forum.
I suppose you can also try the DIP switch for IP Reset.
If none of these work you might post your problem on the NI site forum for professional NI help.