need help with stereo separation

I am using the most current version of Audacity on a Dell laptop running Win 8.1.
My problem is most likely with the windows mixer but I’m not certain. This is the first time I’ve tried recording stereo on this computer.
I have two microphones going through separate channels on an Alesis mixer which has a built-in USB codec. On the Alesis I have one mic panned all the way left and the other is panned all the way right. On the Alesis meters, I see that one mic shows up on the left and the other shows up on the right. I also hear them that way in the headphones that are plugged into the Alesis.
In Audacity both microphones show equal levels on both left and right. There is no separation. I’ve searched the computer for a windows mixer that would allow some control and have searched through the menus on Audacity without success. I’m missing something somewhere. Any suggestions?

Check in the Windows Sound Control Panel that the USB device is set to record 2 channel (stereo).
(The device toolbar must also be set to 2 channel (stereo), which I’m guessing you have done already)