can't hear my recording

When I playback my recording I hear nothing. I see indication that the sound was recorded.

If you’re recording from a USB device, see: http://manual.audacityteam.org/man/faq_playback.html#usb

Unplug the USB microphones. Sometimes, Windows will try to send sound back to the microphone instead of the speakers. You can set that with the Audacity Device Toolbar.

Koz