I have installed MC6 on my Windows 7 - 32 system, but it is not detecting my recording device. I have a RealTek soundcard, and have been to the knowledge base to walk through proper setup. When I go to Preferences ---> Audio ---> Devices, the output is detected, but the recording device area is blank with no option to select the RealTek mic/line input. I have verified that the mic/line input works by simply plugging it in and listening via speakers/headphones. I am hearing the mic or instrument plugged in just fine and at a very good level, but cannot get MC6 to acknowledge the input, therefore, I do not get a VU meter reading, nor will the record function work once a track is armed. Anyone have any idea how to reveal this input to MC6? Thanks!

Welcome to the forum.
Go to the RealTek mixer and select the recording input. It might be set on a different input if have 2 mic inputs on the computer, so maybe the other one is selected.  
Make sure the mic is plugged in when you open MC.

when you say that you go to PREFERENCES>AUDIO>DEVICES and the output is "detected" - did you let the wave profiler run tests on your hardware?

try changing to MME driver mode and let the tests run again and see if that helps.