I’ve had some serious problems with this and I think I’m just too computer illiterate to try and fix it on my own. I’ve turned up playback and recording volume, I’ve gone into the actual Logitech USB mic settings and raised the microphone volume and that didn’t help either. I’m super confused. 
But not half as lost as we are. Please give us the INFO from that pink band above. Which Windows, etc. Don’t abbreviate.
Then tell us in straight narration what you’re doing. “I’m trying to record my voice with a logitech microphone.”
Like this:
http://www.kozco.com/tech/audacity/Documents/PostingQuestions3.pdf
Koz
Also look in Audacity’s Device Toolbar and make sure you are actually choosing the Logitech mic as Audacity recording device.
Gale