"The drive cannot find the sector requested" - External hard disc is not working. Please help me

My 1TB Western Digital External hard disc is not working. My laptop switched off suddenly while copying files. After restarted my laptop, when I try to open my External hard disc drive(G:) I’m getting the message as

"Location is not available

 G:\ is not accessible
 The drive cannot find the sector requested"

The Properties of the drive shows as
Type: Local Disk
File system:
Used space : 0 bytes
Free space : 0 bytes

when clicking My computer->Manage->Disk Management(under Storage in left side), I can able to see my External hard disc drive(G:). The File System shows as “RAW”  before it was NTFS, % Free as 100% but I got around 1TB data. Also I checked in different laptops but it shows the same error.

And finally I checked with “Data Lifeguard Diagnostic for Windows”, it passed the test.

I’m so afraid about my datas stored in the hard disc. All my projects, photos and many important files stored in that hard disc. I dont know what the problem is. I cant find any solutions in Internet. Please help me to solve this problem. Thanks in advance.

P/N: WDBAAU0010HBK

Hello allenarun, it appears that the files are corrupted, you should be able to recover most of them with a data recovery program. Using Google you can find several options. Also check if the link below helps. 

http://community.wd.com/t5/External-Drives-for-Mac/MyBook-initializing-error-cannot-first-aid-repair/m-p/488778/highlight/true#M6507