WD elements 1 TB external Hard disk problem

i am having a WD ELEMENTS external 1TB when i connect it to my computer i cannot find it in my computer but it get recognized and can be found in disk management and it is displayed as 2TB with unallocated disk space and the hard disk could not be initialized actually my hardisk is 1TB it is showing as 2TB how to fix it and recover the data from it and moreover when i used a software to recover the data it is showing as read error(bad sector)

Hello samkumar, welcome to the WD Community. Sorry to hear you cannot access your files. There are several data recovery program you can try, using Google you can find several options. If none of the programs work you can also contact any of the data recovery partners on the WD support page, some of them offer a free evaluation. 

http://support.wdc.com/recovery/index.asp?wdc_lang=en