Reno... USB mics are not the best for Cake products. They are quite problematic and we tend to recommend other better ways to record. Use of a USB interface is the best option with a dynamic or condensor mic that is NOT a USB mic is the best way.
However....
It should show up in the audio devices available list. In preferences, look to see what is available there. Unplug the mic and then reconnect it if you need to. It should show up.
I do not recall a button that turns off the input sources the computer will see. You can choose other sources but still, all the available ones should be in that list.
Perhaps you did somehow de-select it.
We don't like the USB mics because they present to your computer as a soundcard. That means the computer sees and tries to use 2 sound cards. Since the cards each have an internal clock, AND, the clocks are not in sync with each other and can not be synced efficiently, the playback of multiple tracks can often be all over the place. Tracks out of sync, speeding up, slowing down, etc..... Using midi makes it even worse.
Check in the preferences and see what is in the list.
http://forum.cakewalk.com/tm.aspx?m=1618556 also read this post on using USB mics with Cakewalk software.
post edited by Guitarhacker - 2012/02/27 09:07:57