First of all the compability error is'nt about the PC thing or whatever... the compability error comes from the USB your using..
Remember Windows 7 cant be setup if your using a USB 2.0
To indicate if the USB is 2.0 or 3.0 it's easy!
Just go check the part of the USB you insert if you see a blue part it's 3.0 if it's black it is 2.0! you can simple order USB 2.0 still they will exist all the time anyway...