The Loader will detect your 9790 (even with error 507). Click Add to select the new OS. Ensure the box for "BlackBerry 7.1.0 System Software" is checked.
Run the downloaded .exe firmware file (e.g., 9790_7.1.0.1098_P7.1.0.569.exe ). This extracts OS files to: C:\Program Files (x86)\Common Files\Research In Motion\Shared\Loader Files Firmware Change Update on BLACKBERRY 9790 Bold
Introduction: The Legacy of the BlackBerry 9790 Bold The BlackBerry 9790 Bold, released in late 2011, occupies a unique space in smartphone history. Positioned as a smaller, more portable sibling to the iconic BlackBerry 9900, it combined a tactile QWERTY keyboard with a high-resolution 2.45-inch capacitive touchscreen. While modern users are accustomed to OTA (Over-The-Air) updates for iOS and Android, the firmware process on the BlackBerry 7.1 OS-based 9790 was a different beast altogether. The Loader will detect your 9790 (even with error 507)
Download from archive.org (version 7.1.0.42 B37). Install on Windows 7, 8, or 10 (Windows 11 requires compatibility mode). Run the downloaded
Navigate to: C:\Program Files (x86)\Common Files\Research In Motion\AppLoader Delete Vendor.xml . This bypasses carrier locks, allowing any 9790 to accept the firmware.
Use JL_Cmder or BlackBerry Swiss Army Knife (BBSAK) to perform a full wipe. Enter wipe command. Your 9790 will show a "Reload Software: 507" error – this is correct.