Follow these steps to find the problem:
- Make sure that you are connecting only a single device to your computer at a time. Do not have another calibre supported device like an iPhone/iPad etc. at the same time.
- Make sure you are running the latest version of calibre. The latest version can always be downloaded from the calibre website
- Ensure your operating system is seeing the device. That is, the device should be mounted as a disk that you can access using Windows explorer or whatever the file management program on your computer is.
- In calibre, go to Preferences->Ignored Devices and check that your device is not being ignored
- In calibre, go to Preferences->Plugins->Device Interface plugin and make sure the plugin for your device is enabled, the plugin icon next to it should be green when it is enabled.
- If all the above steps fail, go to Preferences->Miscellaneous and click debug device detection with your device attached and post the output in this forum