Download the and run the setup file as Administrator . In the component selection window, ensure you check: Flashmode Drivers Fastboot Drivers
For 2019 and newer Xperia devices, you may need to combine v1.9 with manually updated drivers from Sony’s official Android SDK or use the newer Flashtool driver pack v2.2. However, v1.9 still works for Flash Mode operations on most 2020–2021 Xperia models if you force the driver installation via "Have Disk" method. flashtool xperia driver pack v1.9
Search for "Flashtool Xperia Driver Pack v1.9" on a trusted source like XDA Developers or the official Flashtool mirror. The filename is typically Flashtool-drivers-1.9.exe . Download the and run the setup file as Administrator