# [SOLVED] External hard drive not recognized



## PatrickHill3 (Jul 24, 2011)

EXTERNAL HARD DISC DRIVE NOT RECOGNIZED

This writeup is about problems with my external hard disc drives (EHDD) on my Dell workstation laptop. I had three EHDDs attached to the M4550, a WD My Book 1tb, a WD 500gb My Book, and a Hitachi 3tb. I'll call them MB1, MB0.5 & H1. MB1 died, so I ordered a second Hitachi 3tb. We'll call that H2. 
When it arrived, my M4550 would not recognize it. I tried different USB cables, tried it using the USB cable & power supply of H1, tried it in different USB ports on the M4550, all w/o success. I contacted J&R Music (Amazon partner vendor) and they issued me a RMA and replaced the EHDD. I'll call the replacement H2r.
7/22/11 I received H2r and it still doesn't work. H2r still doesn't work. H1 still works fine. H2r, when plugged in along with the other EHDDs shows up in the device manager (that is, Device Manager shows 2 Hitachi EHDDs); however, it doesn't show up in My Computer, or Windows Explorer. The device runs and the light is on. I even tried removing H1 and plugging H2r into the power supply and USB cable of H1. In that case the Device Manager shows just one, not two Hitachi EHDDs; however it still does not show in My Computer or Windows Explorer.
I just unplugged H2r and plugged H1 back using its power supply and USB cable. It works fine and is recognized.
Then the last troubleshooting step I could think of was this: I hooked H2r up to my old Dell Latitude 820 (XP Pro SP3) and it works fine. Shows up everywhere it's supposed to and shows its file system to be NTFS.
When I researched this sort of situation on the web I saw a number of people with similar situations (and I'm talking here about an EHDD that will be recognized on one computer and not the computer of concern) and the experts who were advising them all said that an EHDD with these symptoms probably had a faulty USB:hard drive interface inside the EHDD box. Of course, because I'm working with a brand new H2r, I can't go inside its case w/o voiding my warranty. Besides, I wouldn't know what to look for anyway.
Since my very new M4550 was formerly handling 3 EHDDs fine I don't think the number of EHDDs is the problem. That's especially so, since (though I hadn't said it earlier), I unhooked all EHDDs EXCEPT H2r and H2r STILL would not be recognized by the M4550. 
My M4550 is running on Windows 7 64-bit professional and is just a couple months old. 
Patrick Hill 7/24/11


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## steely74 (Apr 3, 2008)

*Re: External hard drive not recognized*

does it show up in disk management (not device manager)? right click computer > manage > disk management. if it's there you will likely need initialize it and format it. since it's a 3tb you need to intilize as GPT instead of MBR.


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## PatrickHill3 (Jul 24, 2011)

*Re: External hard drive not recognized*

Yes, it DOES show up in disc management (that is, two identical Hitachi HDDs show up in disc management - I can't tell which is which; however, when I unplug the non-working one, I then see only one Hitachi HDD)


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## makinu1der2 (Jan 1, 2008)

*Re: External hard drive not recognized*

Can you post a screenshot of Disk Management with the drive attached?

http://www.techsupportforum.com/forums/f195/how-to-post-a-screenshot-184291.html


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## PatrickHill3 (Jul 24, 2011)

*Re: External hard drive not recognized*

steely74 - I didn't pay attention to the last part of the message. I don't know what you mean by GPT or MBR? Remember, it shows up fine on my old XP laptop - it can see its file structure and recognize it all the way. BTW, it's file system is NTFS (which I could ascertain when I saw it recognized on my XP machine). I'm delighted, though, that someone knowledgeable is talking w/me. Thanks for your interest.


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## steely74 (Apr 3, 2008)

*Re: External hard drive not recognized*



PatrickHill3 said:


> steely74 - I didn't pay attention to the last part of the message. I don't know what you mean by GPT or MBR? Remember, it shows up fine on my old XP laptop - it can see its file structure and recognize it all the way. BTW, it's file system is NTFS (which I could ascertain when I saw it recognized on my XP machine). I'm delighted, though, that someone knowledgeable is talking w/me. Thanks for your interest.


when initializing and formatting in windows 7 it gives you the option of GPT (GUID Partition Table) and MBR (master boot record). MBR is what we've used in the past. GPT is new and for drives over 2tb.

Using GPT Drives

it will still be NTFS. windows 7 likes you to make it a GPT disk when it's over 2tb. it may be required but I'm not sure as I've never dealt with a drive over 2tb. anyway if they show up in disk management that is a good thing. 

as makinu1der2 said it would helpful to see a screen shot.


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## Rich-M (May 2, 2007)

*Re: External hard drive not recognized*

I am not sure about this, but I would bet this is way too much for usb ports on a newer laptop to support. Multiple usb external drives on a system have long been in many cases an unanswered issue but drives of this size, with lower powered usb ports on each successive laptop release are probably the problem.
Are these all connected to usb ports or are any connected to powered usb hubs by chance?


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## PatrickHill3 (Jul 24, 2011)

*Re: External hard drive not recognized*

makinu1der2,
I'd already made the screenshots you asked for. I'm attaching a screenshot of what I see in MY COMPUTER and what I see in Disc Manager at the same time so you can see that I can view one Hitachi in MY COMPUTER but two in DISC MANAGER. When I hooked the new Hitachi (H2r) to the power supply and USB cables of H1, I got the error message I captured in file Hitachi EHDD #2 hooked to same PS & USB as #1.pdf.

Hope this will help you help me.
Patrick Hill


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## PatrickHill3 (Jul 24, 2011)

*Re: External hard drive not recognized*

Remember, I had a 1tb WD EHDD attached to this computer and working fine with the other two EHDDs before the WD died. I'd had all three attached to a powered hub. For my testing of the new one that doesn't work, I left the other two EHDDs attached to the same powered hub, but did all the rest of my testing with the new H2r attached directly to a USB port on the computer (I'd also previously attached it to the powered hub where the WD had worked fine till it died.


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## PatrickHill3 (Jul 24, 2011)

*Re: External hard drive not recognized*

I've now posted screenshots. Please remember, I'm presently using an identical NTFS Hitachi 3tb EHDD that works fine now. I've not had to change the file type to GPT or anything like that to make it work. I didn't do any formatting or setup to make it work. The one that won't work for me on my Windows 7 new laptop worked fine w/o any formatting or setup on my old Win XP laptop.


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## steely74 (Apr 3, 2008)

*Re: External hard drive not recognized*

the screen shot shows device manager NOT disk management to get to disk management right click computer > manage > storage > disk management


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## PatrickHill3 (Jul 24, 2011)

*Re: External hard drive not recognized*

steely74, sorry bout that! I'm now attaching a screenshot of Disc Management. Showing only the H1 Hitachi, not the H2r (even though it's attached, running, and showing in Device Manager (that I'd called Disc Manager, in my first set of screenshots I submitted).
Patrick Hill


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## steely74 (Apr 3, 2008)

*Re: External hard drive not recognized*

it's showing as disk 4 in the screen shot. no drive letter and not showing a file system though. it shows at the top (right above the good one, look to the right at the free space) and bottom (scroll down to disk 4). go to disk 4 at the bottom, right click on it and format it.


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## PatrickHill3 (Jul 24, 2011)

*Re: External hard drive not recognized*

steely74, You're the man!! It worked. I'm definitely impressed. Now that you've done the important item I asked for, now I see I need a smaller favor -- the newly recognized EHDD will not accept a rename that will display in Windows Explorer or in My Computer. It WILL accept a rename in Disc Manager. I've attached a new set of screenshots that show the two ways the new "J" drive is named. I've tried naming in the format process (reformatted 3 times trying to make that work), plus I've tried in PROPERTIES, and in Windows Explorer's regular RENAME process.
Thanks again for the big favor. Patrick Hill


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## PatrickHill3 (Jul 24, 2011)

*Re: External hard drive not recognized*

steely74,
Please disregard my last request. I rebooted my machine after making that post. The reboot brought in the name change. I now have that new EHDD clearly identifiable, and its name shows up just exactly like it should. Your help has been tremendously valuable.
Regards, Patrick Hill


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## steely74 (Apr 3, 2008)

Glad to help! And glad it was an easy fix


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