My Transcend Storejet 500Gb can't detected.

[Ajiqqq16]

I've got a Transcend StoreJet 25M3 500GB. Before this, my hard disk was working properly and good. Suddenly, yesterday when i connect it to my computer, the hard disk can't detected by my computer. The blue light on the hard disk just work like usually but it cant detected by my computer. My computer show a notification "USB device can't be recognized" How to fix this?
Please help me.. There's got a lot of important data in the hard disk.

 

[Ralston18]

Try a different USB port.

Try a different USB cable - a cable known to be good and working.

Try connecting to another computer(s).

Any error messages?

Does the manual have any troubleshooting procedures?

Check manufacturer's website - forums and FAQ for possible answers.

In the meantime do not attempt to write anything else to the Storejet.

 

[SuperSoph_WD]

Welcome to the TH community, Ajiqqq16!

In addition to @Ralston18's troubleshooting steps, I'd advise you to try uninstalling and reinstalling the external HDD as a device from Device Manager.
Another thing you should check is Disk Management and how the hard drive is recognized there. Maybe changing the drive letter assignment could also help you access your data. If none of this helps, you should probably check your computer/motherboard manufacturer's official website for any USB hub controller driver updates for your model.

Keep us posted & Good Luck!
SuperSoph_WD