I have a Nextel 7520 that I was trying to upgrade to the latest OS from Nextel. The upgrade process started, but now I have a 507 error on the screen and the BB won't do anything. I found this: How do I wipe the BlackBerry using Jl Cmder? - BlackBerryFAQ and followed the steps, but if I take the battery out I can't run the utility and wipe the Blackberry. If I keep the batter in I can wipe the BB, run the Application Loader and start to load the OS, but during the install I get a check mark beside the updating radio and then it just sits there and never goes any futher. Any ideas? Thanks!!

im having the same problem any help would be greatly appreciated

You might try it on another computer.

Are you sure your BB is compatible with the upgrade you are trying to install?