WD External HD wont turn on

hey , my WD hard drive wont start at all. it was working one day then it stopped the next. light wont go on . no sounds within the machine . tried using a different cord and the computer cant detect it ? …
can anyone help me to use it ?
Or if its broken is it possible to get everything that was on the hard drive off it and on to another ?

Hi, try checking on the disk management window to see if it’s recognized there.

Hi I have same problem.  2 TB My Book Studio.  Has worked perfectly for months even after installed Mountain Lion.  I disconnected teh drive when I went on holidays.  Now when I plug it in it is just not recognised by my iMac.  No light, no noise and not showing in Finder.  Time capsule says it cant find it.

It is, however recognised by my Macbook Pro.

What is the disc management window?