To quote another Staff Member, its time to make my mark on :
JL_Cmder, which stands for JavaLoader Commander, is a command line tool provided by BlackBerry. JL_Cmder simplifies accessing the most commonly used JavaLoader commands on your Blackberry.
You must install BlackBerry Desktop Manager or BlackBerry USB and Modem Drivers. Both are available from the BlackBerry website.
Below is a brief overview of the available commands.
deviceinfo - Displays information about the handheld.
eventlog - Retrives and displays the handheld event log.
screenshot - Takes a picture of the handheld screen. (OS 4.0.2+ required)
wipe - Erases the handheld OS. Not really, but that is the simpleist way to explain it. After using the "wipe" command the device will be completely inoperative until the OS is reinstalled. (Error 507 will be displayed on the device)
resettofactory - Removes the IT Policy from the device and wipes the device of personal data while leaving the OS installed and usable. (OS 4.3+ required).
NOTE: If you want to use an unlisted JavaLoader command select Command-Line Usage from the menu. This will display JavaLoader help information including syntax and all available commands.
Vista Users: Right-click on executable and select Run As Administrator.
NOTE: Do NOT use JL_Cmder to "wipe" your device if you are just wanting to wipe your personal data from the device and leave it as it was out of the box. If you use the "wipe handheld" option in JL_Cmder your device will be rendered useless (Error 507) until you reload the entire OS. If you just want to wipe your personal data but leave the OS you can use the "wipe handheld" in the Options >Security Options >General Settings Menu on your device or, if your device has OS 4.3 or higher, use the "resettofactory" command in JL_Cmder. The only difference between the "wipe handheld" in the Security Options on the device and "resettofactory" in JL_Cmder is that "resettofactory" also removes the IT policy on 4.3 and higher OS devices.
Do NOT use JL_Cmder to wipe your device if your device is working fine and are simply attempting to upgrade your OS and you can't get the OS to load or be recognized by Desktop Manager or Loader.exe.
Doing so will most likely render your device useless until you find the root cause of why the OS will not load to the device. Generally, this is caused by not deleting the vendor.xml file(s) or USB issues with the PC.
-- Warning: Please remember that if you do not use this app properly you could lose contacts or other info from your blackberry. Make sure you do a complete back-up of apps and all databases. For App back-up you will need to use BBSak and databases you will need to use Desktop Manager. Myself, TheOnlyJrod, BlackberryOS and any other BlackberryOS Official sites are not responsible for any lost data. If you are not comfortable and/or unsure as how to use this app please ask questions.