Hi there Sai___,
Sorry that you are facing some issues with your WD drive.
So the drive is powering up right?
You can start with something simple as just attaching the HDD with a different USB cable to a different port.
Apart from that, you need to check whether the HDD is recognized by Disk Management and how.
- In case it is recognized over there but it has damaged partitions and/or file system, you will need to use some partition/data recovery software in order to retrieve the data. After that, you can just test the drive with WD's Data Lifeguard Diagnostic tool:
http://products.wdc.com/support/kb.ashx?id=Z5iiMB
- In case it is not, you can go to BIOS and see whether it is recognized over there.
Let me know how this goes,
D_Know_WD