How to Recover my hard disk data ?

My externtal hitachi 1Tb hard drive will not recognize as a drive on my computer. I have only had it a number of weeks, it has not been used a lot and I could not tell you a reason why this may be the case. I have tried several computers, and USB connections and nothing has helped.
There is data recovery software on the drive if that is of use. I would like to be able to use it once to copy the data to another hard drive and then I can send it back on warranty.
What can I do now ?
