BlackBerry Bold 9900 Autoloader: The Ultimate Recovery Guide
: Click "Wipe Device" in BBSAK to clear the current OS (this will cause an "Error 507" on the phone, which is normal). blackberry 9900 autoloader link
What specific (e.g., OS 7.0 or OS 7.1)
BlackBerry Desktop Software or BlackBerry USB Drivers installed on your PC (to ensure the computer recognizes the phone). Flashing Procedure BlackBerry Bold 9900 Autoloader: The Ultimate Recovery Guide