You need to reinstall the os. There's a headline that explains how to install it. Basically, you need to use a program called jclmder( I believe its called) to flash the phone, then reinstall the os using desktop manager. Go on google and type in "revive dead blackberry". That happened to my backup curve a few months ago. You can get it to work. You'll need about2 hours to do this.
It's better to reign in hell, than to serve in heaven.