You can create an environment variable that will show you all of the hardware that has ever been installed in your computer whether or not it is present. With this environment variable you could have seen the duplicate devices and removed them both.

1. Click Start.


2. Right-click My Computer and choose Properties.


3. Click the Advanced tab.


4. Click Environment Variables.


5. Under System Variables click New.


6. For Variable name type: devmgr_show_nonpresent_devices.


7. For Variable value type: 1.


8. Click OK.


9. Click OK.


10. Click OK.


11. Click Start.


12. Right-click My Computer and choose Manage.


13. Click Device Manager.


14. Click View then Show hidden devices.