What do you mean by "reset" the hard disk? Do you mean repartition and reformat the WD Elements drive, so that it's empty as it was brand new? If this is the case I'd recommend that you take a look at this tutorial: How to partition and format a WD drive on Windows and Mac OSX. Note that this is data destructive and you should backup any important data which you might have on it, before you complete the process.
What do you mean by "reset" the hard disk? Do you mean repartition and reformat the WD Elements drive, so that it's empty as it was brand new? If this is the case I'd recommend that you take a look at this tutorial: How to partition and format a WD drive on Windows and Mac OSX. Note that this is data destructive and you should backup any important data which you might have on it, before you complete the process.