In order to fix the problems, I recommend you connect the turntables following the instructions that you can find in the first video tutorial from Google search engine. Once you connect them to your mixer, use the USB cable for the PC connection. Once you finish, launch Reloop Spin and try to calibrate them. If you can't, remove the software from your PC and then install it again. Also, if the devices are not recognized, press Windows + Pause/Break key combination and open Device Manager. Expand the Universal Serial Bus controllers list, right-click on the driver and press Uninstall. Reboot the PC, connect again the device through the USB cable and press Scan for hardware changes icon from Device Manager. If the issue persists, contact the support team using the form from the official website.