Can't Read External Hard Drive

Hey everyone,
I tried loading my external hard drive from my computer, but after I plugged it in and tried to access it, a window pops up that says "The request could not be performed because of an I/O device error. Can someone help me? Thank you in advance.

Open Device Manager and see if there are any errors reported for any of the hardware devices.

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I went into device manager, and my computer reads the external hard drive. But i still cannot access it.

Does the disk show in Windows Explorer or My Computer?

Is this a new device for this machine? If so, and it shows itself as a drive in the above, (and there is no data on the device which you need to save) you may need to format the device.

What does Disk Manager show? (Start, Run, diskmgmt.msc)
or,
C:\WINDOWS\system32\diskmgmt.msc)

Are there partitions listed, or is it all Unallocated space?

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Location: Alberta, CanadaD-A-L Hardware Scan

It shows up in My Computer, but when i try to open it, it says that I cannot access it, and that the request could not be performed because of an I/O device error. Also, I tried formatting the device through my computer but it doesn't work. It just freezes up and after waiting for more than five minutes, I have to just turn off the process. It does not show in the disk manager btw.

I've never hear of a drive showing up in my computer but not disk manager but I have heard it happening the other way around. Is it a usb device? Have you tried it in more than 1 port? Have you tried it in more than one computer (preferably a non vista one)? but if you tried to format it & it stooped then you won't be able to use it on any system until it is reformated. You might have better luck if you try to reformat it in an xp computer. Is it still under warrenty? If so then you might contacting the manufacturer about replacement if not you can open it up & stick it in a desktop if it is a full size drive & take care of it that way. If it is a smaller size form factor then you'll have to buy a kit to connect it in a desktop.

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I've tried accessing this external hard drive through different usb ports and different computers, same result "I/O device error". I've tried formatting it using a windows XP disk but when I reach the screen where I have the option to delete partitions and create partitions, the computer reads the external hard drive as an unknown drive but I cannot do anything to it. I cannot select it to delete the partition or anything like that. This external hard drive was actually a old hard drive from my previous laptop. I just took it out and now I'm using it as an external hard drive. It worked fine before but i think the reason why I'm getting this problem was because my friend was using my hard drive and while it was processing something, he pulled it out. After that incident, this started happening.

something might be wrong with the interface. To rule this out you need to , if possible, take it out of the enclosure & put it in another computer.

__________________
For best results please:
1) State your OS(s), any software involed in your problem, & any major updates (i.e. service pack, version, edition, service release, roll up, beta release, distribution [Linux], etc.) to your OS/software as applicable to your problem.
2) For hardware issues also provide your system information: RAM, processor, etc. in addition to your OS.
3) If you have more than one OS on your computer, how does your problem relate to your other OS(s)? This is especially important for hardware issues.
4) Provide as much detail as possible, being specific as even the most minute detail could help others help you solve the problem. Please tell us what you have tried.
5) Respond with the result(s) of the suggestion(s) from the other users to provide feedback, even if this only means saying "this worked!"

Here is my IDEA, that your flash drive letter is used by other drive.
question:
1. how many logical drive do you have C: D: E: etc
2. Open your External HDD to other PC and change its drive letter

Check what happen.

If the "main" machine you are using (with which you wish to use this "bad" drive) is a desktop machine, I concur with townsbg; ie; Your desktop, as an internal drive for troubleshooting purposes. If need be, disconnect an optical drive and put the hard disk in it's place. Adhere to the existing drive jumper settings from the optical drive and use the same on the hard disk. NOTE: Avoid touching the logic board on the bottom of the hard disk.
Setup Single, Master and Slave Drives in Bios and hard drive Jumper setting

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It's a good day when you learn something
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Location: Alberta, CanadaD-A-L Hardware Scan