WinUSB driver selection

Historically, J-Link needed to use SEGGER-specific USB BULK driver by default. This is because initially Microsoft Windows did not come with a generic USB BULK driver. Starting with Windows 8, Microsoft included the generic USB BULK driver, called WinUSB, in Windows installations, so that vendor-specific drivers are no longer required for new products.

While current J-Link models and hardware versions are shipped to use WinUSB by default (aka driverless mode), there are still plenty of older versions of J-Link out there that are WinUSB capable but were shipped with the SEGGER driver.
Also, for some older setups in the field, when replacing a J-Link in that setup, it may be desirable or even necessary to have a current hardware model running with SEGGER driver selection instead of driverless mode.

Linux and macOS support

Under Linux and macOS there is no SEGGER-specific driver and always the generic USB driver shipped with the OS is used to communicate with J-Link.