Tried umpteen times with amplifi TT, Win7, 64-bit. Press the tone and tap and power on and get only the 4 preset lights on the left illuminated, which I believe means it's in update mode. Launch the amplifi utility, the device is detected (else you get an error at that point), start the download and then the ubiquitous read/write error, every time. I always end up doing the update via bluetooth. Line6, you have a systemic problem with the amplifi download utility and communication with the device.