Hebe, what kind of mic is it?
If you're getting Device is not supported i'm guessing it's a USB mic of some sort.
If it is a USB mic then you may need to install some drivers for it to work properly. Check the website of the manufacturer for drivers for whatever version of windows/unix/mac os that you have.
If you're still having trouble let me know what kind of mic it is and what os you're using and i'll try to offer some additional help.