Windows 7 Forums
Welcome to Windows 7 Forums. Our forum is dedicated to helping you find support and solutions for any problems regarding your Windows 7 PC be it Dell, HP, Acer, Asus or a custom build. We also provide an extensive Windows 7 tutorial section that covers a wide range of tips and tricks.

Windows 7: seagate usb external hdd - showing as 'unknown device'

08 Apr 2010   #1

Windows 7 Ultimate 32 Bit (Build 7600)
seagate usb external hdd - showing as 'unknown device'

I recently upgraded to Win7 Ultimate (clean install) from XP 3/4 weeks ago, and for the last week or so am having problems accessing my USB external drive (although it worked ok at first).

When I connect the drive to my laptop, after a few seconds I hear a windows sound which tells me that the connection failed. In the meanwhile, the drive light displays solid for a moment but then begins to flash at a constant rate that seems faster than when operating normally and the drive cannot be heard.

I went into device manager and checked the properties for the "unknown device" and it was displaying 'code 28' stating the drivers have not been installed, but the last few evenings (after around a dozen or so attempts over several hours during each evening), the drive is somehow detected and is accessible.

I have also tried the following to try and solve my problem

- uninstalled the drive via device manager when displaying as 'unknown device' and rebooted. upon connecting the drive, windows tries to install the drivers but soon displays an error message stating that the drivers are not available.

- updated the bios to no avail

- went into disk management and refreshed drives to no avail

I also tried googling the device id when the drive shows as unknown (which is 'USB\VID_13FD&PID_1618&REV_0100') which brought up many results which seemed to include the line 'pnpdrivernotfound'

I would appreciate any help that anyone can offer, thanks in advance.

UPDATE: last night (8/4/10) my drive was detected after 3/4 attempts (much less than usual) but upon connecting today, i was able to access my drive at the first attempt... computers eh?!

My System SpecsSystem Spec
08 Apr 2010   #2
Night Hawk

W7 Ultimate x64/W10 Pro x64 dual boot main build-remote pc W10 Pro x64 Insider Preview/W7 Pro x64

Welcome to the Se7en Forums! FrEnZyUK

One suggestion given when buying any new external hard drive or flash drive often when simply being used as a storage device is to first reformat the factory Fat volume to NTFS for making it readily available. In 7 the support for Fat and exFat has returned allowing you to simply go into the Disk Management tool and assign a new drive letter for the drive. This will initialize the drive as part of the process making it available again.

If you have only a small amount of files and data on the drive presently you could simply elect to backup them up and reformat to NTFS while in the Disk Management at the same time as you custom assign a new drive letter. Windows will then remember the new letter that replaces the temp letter assigned when working.

With usb not so much eSata drives that are plugged in and unplugged often that will even be more of a help once a reformat is performed in automatically being reinstalled by Windows upon plugging the drive back in if unplugged at all.
My System SpecsSystem Spec
08 Apr 2010   #3

Windows 7 x64

Are you booting with the drive plugged in or waiting until later?

Does the drive behave the same on another computer?
My System SpecsSystem Spec

09 Apr 2010   #4

XP, Vista, W7 64bit Home Premium

Here is a reply from a person who solved a similar problem :

To solve the problem on a Sony notebook running Windows 7, turn off computer, take the battery out. push in the start button for 30 seconds. Meanwhile, unplug your external usb drive from the power source and from the usb. Turn on the computer, plug the power cord back into your usb drive and plug the usb cable into it then plug the cable back into the computer. Windows 7 will detect it and install it. All is well with the world.
My System SpecsSystem Spec
09 Apr 2010   #5

Windows 7 Ultimate 32 Bit (Build 7600)

thanks for your replies guys, i have updated my initial post with the latest situation re: the drive

Night Hawk, when i first bought the drive, i formatted it as NTFS and assigned the drive letter via disk management (i remembered to do this as I had an issue in with a Freecom drive in XP a few years back that would not appear when connected).

Saltgrass, the drive works perfectly on my brother's xp machine (another thing i initially tried when i discovered the problem). I have booted the laptop with the drive attached and also attached the drive after booting in the past with no problems either way.

whest, tried the same method to no avail.
My System SpecsSystem Spec
09 Apr 2010   #6
Night Hawk

W7 Ultimate x64/W10 Pro x64 dual boot main build-remote pc W10 Pro x64 Insider Preview/W7 Pro x64

You could have a bad usb port. If that sees two ports try it on the other. Often when a drive or device isn't being properly detected as it should the port used becomes suspect.

Since the drive works without problem on another machine you know the drive is in working order. So that can be ruled out.
My System SpecsSystem Spec
09 Apr 2010   #7
not so gray matter

W7 Ult. x64 | OS X

Test if you can connect to other devices via that usb port... follow Night Hawk's advice.
My System SpecsSystem Spec
09 Apr 2010   #8

Windows 7 Ultimate 32 Bit (Build 7600)

all other devices work fine, my usb sticks and printer work fine on all ports. i'm actually surprised the drive connected first time tonight
My System SpecsSystem Spec
09 Apr 2010   #9
Night Hawk

W7 Ultimate x64/W10 Pro x64 dual boot main build-remote pc W10 Pro x64 Insider Preview/W7 Pro x64

I've seen that a few times using one brand of flash drive where it would be sslowwww or not work on a port or certain usb hubs while it would work normal on the next port or hub on another system. Some tend to draw more power then others.

This is likely what you are running into there where the bus is being pulled down a bit by the draw from the drive. I saw that tendency with a $40 6 port hub not working for anything while a cheapo 4 port for half the price sees all brands work without problems simply by providing more current.
My System SpecsSystem Spec
10 Apr 2010   #10

Windows 7 Ultimate 32 Bit (Build 7600)

seems like this problem has cleared (so far), the last 3 times i booted my usb drive (after windows has booted fully) it has been detected first time, and on all ports (yay!).
My System SpecsSystem Spec

 seagate usb external hdd - showing as 'unknown device'

Thread Tools

Similar help and support threads
Thread Forum
Seagate 500GB HD showing 2TB, Unknown, Unallocated, Read Only Bad disk
Hi. I have a Seagate Goflex 500GB external hard disk. When I connect it to my laptop, it doesn't appear in my computer, and I have attached the screenshots of Disk Management and MiniTool Partition Wizard. The hard disk is behaving this way when I removed it from my laptop while it was copying a...
Hardware & Devices
Seagate drive won't backup for reasons unknown.
I have a Seagate Free Agent Go Flex Desk backup, which came preloaded with a Memeo backup program. Recently I keep getting messages saying, "Failed to back up (various different files)" and "Failed to back up current session." One other message said "No backup plan found." When I watched what...
Backup and Restore
New Seagate Expansion External Drive not showing up in 'My Computer'
Howdy, I bought a new computer with Win7 about a month ago which came with a 1TB Seagate hard drive installed so I decided to replace my previous 250 GB Aulartek External with a 1TB Seagate External Drive. Well ... to make a long story short I tried installing the new Seagate 1TB Expansion...
Hardware & Devices
External hard drive found as unknown device
I have a LaCie external hard drive which works fine on other pc's running Windows 7 Ultimate, but on this one it is an "unknown device". I have tried it in different ports but with the same result. I've checked with Windows Compatability and the exact model is listed there as being compatible. I've...
Hardware & Devices
Graphics Card Showing up as "Unknown Device"
My ATI Mobility Radeon 9600 is showing up as a unknown device in device manager and i can't install the driver because it wont install a standard VGA driver :confused:
Unknown Device, External HDD
Hey! Yes I am new to the forum here, as I am to Windows 7, but I have to give it up for Windows this time, Windows 7 is actually more stable, faster and easier to operate than even today's Vista. Although... I have an Asus M51Se notebook. And it has not a huge drive, so I store most and all my...
Hardware & Devices

Our Sites

Site Links

About Us

Find Us

Windows 7 Forums is an independent web site and has not been authorized, sponsored, or otherwise approved by Microsoft Corporation. "Windows 7" and related materials are trademarks of Microsoft Corp.

Designer Media Ltd

All times are GMT -5. The time now is 21:24.
Twitter Facebook Google+ Seven Forums iOS App Seven Forums Android App