I have an external hard disk drive. It has a 160 GB transcend, Yesterday, all things were working OK, but today, when I insert the disk, my laptop gets hung. The disk is being detected, but after opening, it is not getting open up. It shows a pop up message? You can use your disk after formatting it?. I have tried to scan it by antivirus but it?s not getting scanned. I want to save my data. The disk?s name I had given was ?Transcend?. Today, It is not showing the name ?local disk?. How can I recover my Hard disk drive? I wonder, How it has broken down all of a sudden?. Is there any way to save my data? I don?t want to format it. How can I get my data? Is there any software to repair my hard disk?

Firstly,recover your data on the external hard drive with third party data recovery software.Then you can format it to check out whether it can be fixed.
For data recovery program,I have a professional one on my computer that can recover data after deeply scanning your hard drive to look for lost data due to drive crash,system sabotage, virus attack etc.You can download it and scan your hard drive for free to preview whether your data can be recovered. http://www.any-data-recovery.com/product/datarecoveryprofessional.htm

Professional services will help you out. Online Consultation

OK! It sounds like your drive has got some problems.
In order to get the inner stored data, you should always act carefully:
1. Do NOT click "Yes" to format the drive in case that the formatting process makes things worse.
2. Do NOT attempt to write anything new on this hard drive in case of any data loss.
3. Download data recovery software to help you. There are many data recovery tools out there. But, no all of them could be efficient and useful enough. You should pay much attention to opt for a proper one.
So, if you are interested, you can firstly try an external hard drive data recovery freeware:
http://freeware-fix.blogspot.com/2013/03/external-drive-data-recovery.html
It always can thoroughly scan a hard drive and do its utmost to restore all scanned data back successfully.
Here is some detailed information of this freeware:
http://www.freeware-fix.blogspot.com/2013/03/unformatted-hard-drive-recovery-freeware.html
4. Do not save or back up all the restored data on the same hard drive in case of any data loss.
5. After the data recovery process, simply format this drive to see whether it can work functionally as before.
In the future, you should learn a lesson to be more careful about your data and always back it up well.