External hard drive refuses to be detected

[LyricalKaos]

I'll start by saying the external hard drive i'm using works off and on. For the last while (about a year) it refuses to be detected by my computer. Earlier today, i decided i would try it again, and to my surprise it works. I've been wanting to reset my computer for a little while now, and thought this would be a good time to do it. So i back up all of my important files, including a teamspeak server for my friends, reset my pc, and plug the drive back in. It doesn't show up. I've been looking around on the internet to find a solution to my problem, but i couldn't find anything. I looked in the disk manager (have no idea how to use it), and it is there, but there are 4 portions of the hard drive. It is a total of 1 TB but it comes up as: 80.42GB Unallocated | 179.37GB Unallocated | 259.79GB Healthy (Primary partition) | 411.92GB Unallocated. For the healthy partition which contains all of my data all of the options are greyed out except for "delete volume" and "help" I really need to access this data as fast as possible as it contains important files. Is there any way to retrieve all of those files?

 

[LyricalKaos]

I've since found a program called MiniTool Power Data Recovery that allowed me to recover the files from the drive.

 

[D_Know_WD]

Hi there LyricalKaos,

It's great you've managed to retrieve your data.

Yet, as there might be something wrong with the drive, I believe it would be nice to back up the important data stored on the drive and test it afterwards: http://www.tomshardware.co.uk/forum/282651-32-best-diagnostic-testing-utility

See if there are any abnormal values in the SMART report. You can post a screenshot as well.

Cheers,
D_Know_WD