To connect the grey Bosch WAP to a desktop computer, first connect the smaller ends of your cords to either the front or back Mic/Line In & Speaker/Line Out jacks. The pictures below show the location of the jacks on both the front and back. They are indicated by either the pink/blue for Mic In, and green for Speaker Out.
The cables should look like this or similar:
Next, connect the larger ends of each cord to the grey Bosch WAP unit. Pay close attention not to put the wrong cord in the wrong jack. Most of the time, the Mic In on the computer will be on the left of the two jacks, which is the same way on the Bosch WAP. Finally plug in the power cord to the Bosch WAP noting that it needs to be firmly pushed in. If the power cord is not plugged all the way in, it will be loose and can be easily removed.
Once the power to the Bosch WAP is plugged in, the outer-most blue lights should begin to flash. They will remain flashing until one or more of your microphone units are powered on.