Hard Drive not showing on laptop

when i plug hard drive in the WD smartware button will come up, but the orange hard drive button that accompanies it will not come up. I have restarted computer and tried hard drive in 3 computers and still will not show. I have just purchased a new hard drive today to get rid of old one but cannot get my 750gb of data off my old one.
I have searched everywhere online and cannot find any answers relating to mac computers.
I am in desperate need of help as i need my data!!

Hello there and welcome to the WD community.

You can try a different USB cable or a different port, also try to check if you can connect this drive on a different computer to see if the unit comes up.