MY TOSHIBA 160 GB USB EXTERNAL DRIVE KEEPS CLICKING AFTER POWERING ON AND THE PURPLE LIGHT KEEPS FLASHING BUT THE COMPUTER DOESNT RECOGNISE THE CONNECTION

Was it working before with the same computer ? Try with a PC is you can, maybe the drive was has filesystem that mac cannot see by default (like NTFS).

Try connecting this USB hard drive to another computer.
The clicking sound is known as the "click of death" the read write head is banging back and forth and is a sign the hard drive is faulty.

Hi,

In most case's only one USB needs to be connected, but you need to load the driver for it from the disks which you would have received for it.

Hope this helps.

Thanks

Jason

Go to computer management by right clicking 'my computer' then selecting 'manage'. Then select disk management. Find your externel hard drive there ( it should be there). Then right click on it, and choose assign drive letter. Just choose a letter in the middle of the alphabet like N or O, then enter. You should see the icon of your external hard drive inside 'my computer'.

Clicking sound is the motor trying to move the head. Unplug it and try gently tapping it from the side, it seem to help time to time with some drives. If that doesn't work, put it in a zip-lock bag and freeze it for 40 minutes and try again. If still doesn't come up, you're out of luck.

audible clicking sound? doesnt sound good. clicking sounds are usually signs of failing HDD....

change the cable then try again

A hard drive that is making clicking noises is faulty.
Replace the hard drive in the portable Toshiba case.

If your hard drive is recognized by your computer try opening control panel,to administrative tools,to Computer management,to storage, to disk management,by right clicking on drive you can format that drive or delete it.

The USB cable you're using is too long.