Flashtool 0.6.6 Windows -

Yes, but you must disable driver signature enforcement and run as administrator. The flashing process itself works perfectly.

This is the most critical step. Windows 10/11 default drivers often do not recognize the "Flashmode" or "Fastboot" state of legacy Xperia phones. You will likely need to install the package. This package includes: Flashtool 0.6.6 Windows