i'm not sure if its crashed failure or broken. but the physical look is perfectly intact

i've got this cutie external hard drive that i have been using for at least 1 year. but i think its more than 3 yrs old cos it was passed down to me. it crashed/failed a few days ago. when i plug it into the computer, the pc does not even sense the device being plugged in.
i think it may be broken as i have dropped it a few times.

The power light(green) shows up, but my pc just doesn't seem to recongnise it

It's not in Device Manager, not in My Computer, not in Add or Remove hardware.

PS. list of things I've tried:
-run --> cmd --> diskmgmt.msc (nothing there except C:\ and D:\(CD drive))
-tried unplugging and replugging it on 4 other PCs

The hdd inside that is made by IBM Travelstar, model djsa-200 , and Hitachi's diagnostic tool is listed as working with this hdd. Download the diagnostic tool and make a bootable CD and run the test. From what you have told us, I doubt the hdd is working anymore. Good luck.

http://www.hitachigst.com/hdd/support/download.htm

which application do i download.

do u think i can get back my data from the hardrive ?

Try the Drive Fitness Test.

There are forensic retrieval techniques out there that may be able to get you data back, but it would be expensive.

so i have to extract it into a cd rite?-- sorry i'm not very intelligent

There are instructions at the site that the link takes you to.

the software cant run on my pc. the computer will force shutdown on its own. is there another method?

HELP HELP!!

Personally, I think that if this hdd won't work with any of the computers that you have tried it with, and the fact that you have dropped is a couple of times, I would call it quits. Hard drives can't take a lot of hard knocks. It's toast, done, kaput, dead.

but if i send for repair can i get my data back??

It's possible but not guaranteed and can get expensive. I would take it apart and check for loose or damaged parts and see if the connection to the drive is solid. If it's a mechanical failure of the case, you can get another one. It's a shot in the dark

damn. but thanks anyway.i guess i jus gonna send it for repairs and recover my data