This happened just now. I was transferring files from my "videos" to my hard disk drive (WD elements) but then I accidentally unplugged my laptop and it shut off (I took off the battery). When I opened the laptop, I can't see my HDD anymore and the light isn't blinking. My laptop can recognize the HDD but it's not appearing on my computer. What should I do?
I tried to make it work on my other laptop but it doesn't work.
^ I think this was to an External HDD, not the OS internal laptop, although what you stated is correct; since it is not to the OS HDD win repair most likely will not fix.
First off, it hard to tell what got clombered when power was removed.
If in a write operation most likely your Partiton information was corupted since you no longer can see the drive. Also possible the FAT (File Allocation Table) was corrupted.
You can try EasyUS (Free for consumerers) http://www.easeus.com/
There are other programs that can recover a lost partition?files< just google "Recover Lost Harddisk files.
If these do not work, You learned a lesson - Never do a large file transfer on laptop with out the AC power adaptor and at least a 10 Min battery runtime, and equal to time absent from laptop.
many laptops will go into a sutdown mode when battery hits a set % of low battery. This would/should cancell writes then shut laptop down in an orderly faction. Check to see if you have this available as a setting.