WD My Book Live -- green light not on, does not install

Hello, I have a WD My Book Live that has been working flawlessly for quite a while. My computer hard drive failed last week and it confirmed how glad I am to have the My Book Live. Now that I have replaced my computer hard drive, I am trying to reinstall the WD My Book Live. I have found that when the My Book Live is plugged into my router and plugged in to power, I hear/feel the drive operating, but I do not see the green light that used to be on when the drive was running. 

Because I am not getting the green light on the front of the My Book Live, the software installation cannot complete. 

Please help me understand what I am experiencing. I’m panicing a little since many items are backed up on the My Book Live. 

Thank you,

Patrick

What color light do you see? Compare with the manual to see what color matches the one you have.

Also check the back LEDs and compare to manual.