: Connect the device via USB, open the wizard, select the applications/OS version you wish to install, and follow the prompts. : For modern PC compatibility, you may need to use a legacy version of BlackBerry Desktop Software specific OS version (like 7.1) for your Bold 9900, or are you trying to bypass a specific error BlackBerry Classic Q20 Autoloader: Download & Install Guide
Ensure the filename reflects "9900" or "9930" (the CDMA variant). Do not use a 9700 or 9780 autoloader on a 9900; the radio hardware is incompatible, and you will permanently brick the device. Blackberry Bold 9900 Autoloader
Ensure BlackBerry Link or Desktop Software is completely closed. : Connect the device via USB, open the
Do not run the Autoloader blindly. Preparation is the difference between a revived phone and a total brick (though bricks are rare with the 9900). Ensure BlackBerry Link or Desktop Software is completely
, "autoloader" usually refers to a simplified executable (.exe) file used to flash or reinstall the device's operating system (OS 7.0 or 7.1). Unlike the newer BlackBerry 10 devices, the Bold 9900 typically requires the or the standalone AppLoader utility for a clean install. How to Reinstall the OS (Autoloader Method)