i'd like to see which model it is...i'm seeing all number of customer issues with certain models of dynex usb mics and headsets...one instance looked to be a low power on the usb port issue...has me that this may be a similar issue
i only have 2 usb ports.ive tried both and nothing works
only 2 usb ports total? what are you using a laptop? do yourself a favor and get something like this...http://www.amazon.com/gp/product/B000N8RK7Kit has a really long cord...the mic is very clear in every application i've tried it in...and the headphones are very comfortable.
Have you checked that you have the correct sound input selected under the 'preferences/game sounds/microphone'?
what do they look like.and how much are they usualy?