When i hooked mine up it set it as COM 21, which wasnt an option in flexi. I had to go to device manager and manually pick another port. I use COM 2. Works great now, Fixed my alignment issues also. My plotter wouldnt align with the reg. marks from flexi until I put in the USB Adapter. I dont have optical head so I have to do it manually. Im just glad i can do contour cuts around prints now.