Windows 10 typically downloads the driver automatically when you connect the amp via a USB-B cable.
Connect the Katana-100 MkII to a USB 2.0 port and turn it on. boss tone studio katana 100 mk2 download windows 10
If it doesn't auto-install, download the specific Katana Driver Ver.1.0.1 for Windows 10/11 from the BOSS website. Windows 10 typically downloads the driver automatically when