External hard drive not getting detected on Windows 7 computer

Sorry for bringing this back to life, but I appear to be having the exact same problem. The lights on the front of my Hitachi light up, but otherwise there's no "movement". I've plugged it in to two other PCs, and it hasn't been recognized on either one of those as well. It hasn't been dropped or anything, and in fact has been sitting unplugged for a month or two since the last time I used it.

I tried the diskmgmt.msc thing, and it doesn't show up there.

I did the Windows Fix It thing, and got the same response, "issues found : hardware changes might not have been detected" but no further assistance on that subject.

I don't know what a USB hub is, sorry. But it's plugged into one of the USB ports on the back of my computer.

Any help would be appreciated. This thing isn't that old and I'd really hate to have wasted the money I spent on it.

This appears to be an  outstanding Microsoft software bug because I ran into a problem where I used the built-in Windows 8 back-up utility running on my HP laptop writing to an external USB hard drive. The back-up failed after a couple of hours because it was unable to write one of the files.

I re-boot the laptop thinking that all would be OK but the operating system no longer recognized my external USB hard drive.  Going into disk management, there is no volume information available or drive letter assigned to the external USB hard drive but it is defined as healthy (GPT protective partition).

On the same panel at the bottom of the screen , I can right-click on the blue line for the external USB hard drive (Disk 1) but the only option available is Help and all others including Open, Explore, Make Partition as Active, Change Drive Letters and Paths, etc. are greyed out.

At first, I thought my old external USB hard drive failed and I purchased a brand new 1TB Western Digital Elements external USB hard drive. After automatically recognizing the new hard drive, I encountered the exact same software failure described above caused by using the back-up utility because it looks like their error handling routine is faulty and unable to recover properly.

After an hour on the phone with Western Digital support, the technician could not resolve my problem and suggested I go back to the store and try to exchange it which I did. However, I will not touch the Windows 8 back-up utility fearing the same result corrupting my two previous external USB hard drives.

I tried what you said and diskmgmt.msc doesnt seem to detect it even after i tried with youre diagnostic tool. What should i do now ??

Hi Da Ninja,

What happened when you ran the diagnostic tool?

Were there any errors you can post to this thread?

How is the device connected to your computer? Are you using a USB hub between the device and your computer?

What is the model of your computer?

As this is a new hard drive, have you formated it? Does it need formating?

I suggest following the manufacturers troubleshooting steps outlined in the page linked below:

http://www.hitachigst.com/support/downloads/index

Chris

Microsoft Answers Support Engineer

Visit our Microsoft Answers Feedback Forum and let us know what you think.

Hi,

Step 1: Check if you can see the drive in Disk Management.

Check if you can see the hard drive in disk management and if its detected, then assign a drive letter to it.

TO open disk management:

a. Click on start button.

b. Type diskmgmt.msc in the start search box and press enter.

c. If you can see the drive, then mark the partition as active.

d. Right click on the partition and mark as Active.

Refer this link for steps on how to add a drive letter to the disk.

http://windows.microsoft.com/en-US/windows7/Change-add-or-remove-a-drive-letter

Step 2: Run Microsoft Fixit diagnostic tool.

If you cannot see the drive in disk management, then refer the link mentioned below and run the Fixit diagnostic tool to automatically diagnose

and repair problems with devices when the device manager does not detect your hardware.

Hardware devices not detected or not working: **** http://support.microsoft.com/gp/hardware\_device\_problems

Regards,Afzal Taher-Microsoft Support.Visit our Microsoft Answers Feedback Forum and let us know what you think.