WD Passport 1 TB data transfer issues - please help!

I bought two WD Passport external hard drives (USB 3.0) from Amazon about two months ago.

Precise model name -  Western Digital My Passport 1 TB USB 3.0 Portable Hard Drive - WDBBEP0010BSL-NESN 

 

I then transferred some large quantities of data onto these drives (several hundred GB on each drive, each movie file below 2GB).

Now one of them has started acting up - it won’t get recognized by my PC (a Toshiba notebook with a Windows 7 OS) in the sense that the little window that pops up when you attached the drive to the USB port, doean’y show up. After much time, the drive can be seen in one of the computer hard disk drives on the “My Computer” page. But then I cannot transfer any data either to or from the drive.

What’s particularly galling is that it was functioning perfectly until yesterday morning. No issues whatsoever. Then bam! just like that, it won’t work.

Any tips or help from experts, or those that have experienced similar issues would be most appreciated! I’m not a very tech savvy person, so please pardon my ignorance about any issues. 

Thanks!

 

 

Check the unit on the disk management to see whats the status.