The Microphone Mix plugin will pick up any standard Windows audio device. You should ensure your audio device is plugged in before starting PlayIt Live. It is initialised on startup.
Does the Pyle mixer actually have a USB sound card ?
A quick Google suggests it will play files from a USB stick but doesn't strongly suggest a "normal" USB sound card.
If you can use it with other Windows software (such as Audacity) then it should work with PlayIt Live.
Having said that, for most applications, if the mixer is suitable then just looping PlayIt Live's audio via a mixer channel and mixing in the mic on the mixer is better than using the Microphone Mix plugin (which is most useful with USB microphones).
Asegospelradio
I just paid the $15 for microphone mix plugin for live shows... However in the configuration panel it does not recognize the Pyle mixer I have nor being plugged into CPU... What shall I do so that my microphone is recognized?
What am I to do? I need help....