Mackie C4 not showing up in control surfaces

I have a Mackie MCU Pro, XT and C4. All 3 work on my desktop. I recently moved everything to a laptop. But only the MCU and XT show in my control surfaces on my laptop. All midi ins/outs of the MCU Pro v3.1 are selected in devices. Why won't the C4 show up in the control surfaces? Thanks, Kevin This is a Dell Studio 1749 Laptop with Intel I5 CPU running win7 64bit.

Hi FBB, it's attached via the midi ports of the MCU pro, and all 4 ports of the mcu pro show up in devices.

Problem solved, but mystery remains. I had never used the mackies on this laptop before, or at least that's my recollection. So when I loaded a project and saw the MCU and XT already listed, I thought that happened automatically. So upon not seeing the C4 I thought something was wrong. It must have been your question that sparked me to remember that there is an 'Add Device' button in the top right corner. So long since I had used it i forgot entirely about it. I used my last system for years so totally forgot about the need to actually add the device, not to mention I didn't have to add the mcu and xt, they just appeared (magically, unless I forgot I once used this laptop with those control surfaces. And that is where the mystery remains). So eveything's working again. Thanks for responding FBB. I beleive it was your last question that sparked the solution. Kevin