getting two USB headsets to record on Audacity---PLEASE HELP!!!!!!!!

My friend and I are having problems with our two Logitch 250 USB headsets. the problem is when they're both plugged into my PC...only one will work.

Please, please, PLEASE!!!!, if you have ANY idea of how to get two USB headsets to record on Audacity...tell me!!!

Thank you,
Ganfon