My 500G Lacie external drive is no longer detected by windows. Sometimes it will say the USB port or device is mulfuction. Sometimes it does not detect it at all.

For Windows XP and later, or Mac's OS9 and later, it should auto detect when it's plugged into a USB port. Large drives can sometimes take a little while to be detected, shouldn't take longer then 45-60 seconds, unless you're having other problems with the USB port. If it doesn't work in the first USB, try a different one, preferably on the back of the computer (some computers have front USB ports that aren't the same quality, power, and speed as the rear ports). If it doesn't work in a second port, try it on a different device that can read from the USB (another desktop or laptop, and some tablets and phones can do this).

A USB hard drive is a portable external storage device that works just like a conventional hard drive.

The device is simply plugged into a USB port on your computer as you would connect a flash drive.

Unlike a flash drive, however, a USB hard drive can store a much larger amount of data.

If your computer will not recognize your USB hard drive, you can try troubleshooting steps to resolve the problem.

Plug one end of the USB cable into the port on your hard drive and plug the other end into the USB port of your computer. Ensure that both ends of the cable are connected securely.

Open "My Computer" (Windows XP) or "Computer" (Windows Vista/7).

The USB device should be listed as "removable disk" once it is plugged into the computer.

If it is not listed among the available drives on your computer, proceed to the next step.

Ensure that the data cable is working properly.

Try another USB cable if you have one available.

Disconnect all other USB devices from the computer as they may interfere with the operating system detecting the external hard drive.

Reboot the computer if the USB hard drive is still not recognized.

Plug the USB cable into another USB port and check to see if the device is detected.

If you are using a USB hub, remove the device and plug the external hard drive directly into a USB port.

If the computer still fails to recognize the device, the external hard drive itself may be experiencing a hardware problem.

Check the status of the hard drive in the "Device Manager" window. Under Windows XP, right click "My Computer" and select "Device Manager."

For Windows Vista and Windows 7, click the "Windows" button in the lower left corner of the screen, then type "Computer Management" in the search bar and press "Enter."

Select "Device Manager" in the "Computer Management" window. In the Device Manager window, click the "+" sign that appears beside "Disk Drives."

If the external drive is not listed, click "Other Devices" in the Device Manager window and see if an "Unknown Device" appears.

The external hard drive may have been detected but the device is not working properly.

If it is still under warranty, take the device to the computer store where it was purchased to have it repaired or replaced.

Hope this helps

click start control panel administrive tools ,computer management ,device manager look through all of your devices if you see a yellow question mark?or exclamation mark ! or red x
right click to reinstall drivers or
if you can see your usb but its not working
ports(com&lpt)right click update driver
sometimes the wires inside the cable will be damaged due to bending or stretching or placing heavy equipment upon the cable,
just replace the cable of the hard disk, when you plugged the external disk drive you got that windows could recognize the USB device change the cable everything should work fine again,
check the USB leads that attach to the motherboard usually red-white-green-black make sure they are securely seated and have no dust build up on them dust will cause static and a lot of unforeseen problems
hope this helps

click start control panel administrive tools ,computer management ,device manager look through all of your devices if you see a yellow question mark?or exclamation mark ! or red x
right click to reinstall drivers or
if you can see your usb but its not working
ports(com&lpt)right click update driver
just replace the cable of the hard disk, when you plugged the external disk drive you got that windows could recognize the USB device change the cable everything should work fine again, sometimes the wires inside the cable will be damaged due to bending or stretching or placing heavy equipment upon the cable,
check the USB leads that attach to the motherboard usually red-white-green-black make sure they are securely seated and have no dust build up on them dust will cause static and a lot of unforeseen problems hope this helps
hope this helps

Hi
try to check your hard drive on other computers and see if you could access your files or not.

1-other computers can detect your HDD:
1-1-software issues on laptop:
try to update windows or OS of your computer for most updated driver
1-2-hardware issues on HDD:
1-2-1:you have a broken/shacked/shocked/stroke HDD:
go for replacement or warranty service.
1-2-2:USB/fire wire cable problem:
replace it
2-3:you have a damaged/weak USB port on your laptop that couldn't fully supplied the minimum needed current:
repair the damaged port via certified expert or manufacturer warranty/repair service.

2-other computers can not detect your HDD:
2-1:cable problem
2-2:you have a broken/shacked/shocked/stroke HDD:
go for replacement or warranty service.

best regards

maybe is Lacie transformer defect, try replace-it

I devised these simple steps that tend to remedy quite a few issues with most USB portable / external hard drives and devices (though not always)

A few things to check but assumes USB and Windows for other interfaces / operating systems similar steps may be adapted to suit.

1. Ensure it is connected directly to the computer to a USB 2.0 port not a USB 1.0 port as this can have effects on performance and reliability

2. Use only the cables that came with it NOT one that fits that may have been lying around or is longer. Not all USB cables are equal even though they should be)

3. Do not connect through an external USB HUB unless that hub is USB 2.0 AND has its own power supply.

4. Use ONLY the power supply that came with it if it has an external power supply Don’t use any other unless you know it has both the same voltage and current rating e.g. 12V 500mA anything rated below that would not work properly.

5. Always use the same port for connecting your devices. Some devices do not like being switched about. If switched they may want to install software / drivers again. This can be especialy true if you move a HUB to another port

If you checked and fixed anything there and still have issues then check your hardware from CONTROL PANEL / SYSTEM / HARDWARE.
Any exclamation marks by hardware need fixing before you investigate any further

I have the same issue, however with my verbatim 500g its ok. i believe it is because the lacie is a desktop external and therefore is compatable with windows xp and 7 alone.
Verbatim is a "portable" external hard drive which makes it compatible with several different systems. I would suggest returning it, I just formatted my old verbatim harddrive and set up mediaasharing. Through my router. You can actually route the lacie harddrive by going to my computer and right click the icon. Next go to share with; advanced settings and allow all. Then when you turn your ps3 on search for media servers... I would suggest to google media server for ps3 to get it all seet up. GOOD LUCK

Are you sure it is not a power problem? If the drive has an external power supply then then will not be the case, but if not, the USB port might not provide enough power.

Also check out: http://www.devicedriverfinder.com/blog/device-errors/external-hard-drive-troubleshooting

I ran into this issue this week with my lacie big disk 500G external. Unit would power on when plugged into a pc blue light would flash and nothing no connection ding from windows.
Blue front light would flash repetedly slight ticking sound from drives but no connection i finally fixed this and gained access to my data by opening up the case and pluging my pc 12v connectors into both drives to power them up but leaving them connected to the lacie internals worked instantly and ive since copyed all my data off my 500 and will just transplant the drives to internal use on my pc. you cannot connect the drives internally and then copy the data due to the fact that they are raid 0 stripped drives so this hybrid setup works if your external case isnt powering up the drive correctly as mine wasnt.