You could just reload the OS.
Install the BB desktop manager.
Also locate the handheld OS for your device somewhere on the sprint site.
Follow these steps.
Connect your BlackBerry smartphone to your computer.
Open BlackBerry® Desktop Manager. Note: BlackBerry Desktop Manager may display "Disconnected." If this is the case, proceed to the next step to correct the problem with Application Loader.
Click Application Loader. The Application Loader Wizard appears.
Choose the port that the BlackBerry smartphone is connected to and click Next.
If prompted, type your BlackBerry smartphone password and click Next. The Device Application Selection screen appears.
Select the applications that you want to install on your BlackBerry smartphone.
If the Device Backup screen appears, choose whether or not to automatically back up the data on your BlackBerry smartphone. Click Next.
The Completing the Application Wizard screen appears, displaying all the software that will be installed on your BlackBerry smartphone. Click Advanced and make sure that Erase all application data and Erase all currently installed applications are both selected.
Note: If the application loader tool was not able to access all of the data on your BlackBerry smartphone, then the following two fields are grayed out: Erase all application data and Erase all currently installed applications.
Select Do not automatically create a backup and click Next.
Click Finish. The BlackBerry Device Software will be installed on your BlackBerry smartphone. Do not disconnect your BlackBerry smartphone until the process has completed.