Problem: Had the same problem. Plugged Kobo Glo into Windows computer, the device showed "Computer detected" and I click "Connect". Then, even after showing "Connected and charging", it would not show on my computer.
Solution:- Make sure you are using a data-transfer USB cable, not a charging-only cable (they look the same and plug into the same ports)
- If you are using Windows, use a USB adapter/dongle or USB hub (Mac seems to connect without it)
- You may need to use the Adobe Digital Editions software to authorize/activate your device
- You may need to use the Kobo app to authorize/activate your device
- Ensure your cable works with other devices to transfer data between your computer and device