External hard drive has split personality
February 28, 2007 8:18 PM   Subscribe

Why does the drive letter for my external hard drive keep changing?

I have a Seagate external hard drive hooked up to my Dell Dimension 8400 PC running Windows XP Media Center SP2. Occasionally, the drive letter for the Seagate will change for no apparent reason. I'm using Memeo backup, and since Memeo is currently looking for an E: drive and the Seagate has decided to be the J: drive, nothing is getting backed up. Previously I've sighed and created a new backup plan on the current drive letter, but this is getting old and isn't solving the problem. Does anyone have an idea why my hard drive has a split personality? Is it something with the drive, or with my computer? I've had the drive for 15 months and the computer for about two and a half years. I started using Memeo about a year ago.
posted by Joleta to Computers & Internet (10 answers total) 1 user marked this as a favorite
Best answer: So is this drive jumping back and forth between E: and J:, or did it just move from E: to J: at some stage in the past and then stay there, or what?

The standard way to fix a Windows XP drive letter, which should work provided it's the same drive being plugged into the same computer, is to right-click My Computer, select Manage->Storage->Disk Management, right-click the device or partition (should be obvious which is which, from size if nothing else) and select Change Drive Letter and Paths.

If that doesn't make your selected letter stay put, something else is going on.
posted by flabdablet at 8:42 PM on February 28, 2007

I am pretty sure you have to have administrator privilege to do what he just said.
posted by Steven C. Den Beste at 8:48 PM on February 28, 2007

I don't know why, but it sounds like your computer is reinstalling the drive once in a while and kicking it down a letter each time. Maybe a bad USB plug or socket?
posted by lee at 8:57 PM on February 28, 2007

I have six USB ports, including my front USB. Whenever I plug my mp3 player into a different port, it changes the drive letter. Maybe that's what happens to yours? Or do you plug it into the same port each time?
posted by Verdandi at 9:17 PM on February 28, 2007 [1 favorite]

Along the same lines of lee, are you using some sort of off-again / on-again USB device (e.g. MP3 player, camera)? Some of those will take over the next available drive letter. Possible the hard drive and something else USB are fighting for the drive letter.

I'd also try giving it a letter manually as flabdablet said, use something farther down the line of letters that's less likely to conflict. "M" or something.

Another thing to try is to see if there a device drivers available for your machine, particularly the motherboard (assuming we're not talking a USB hub of some sort here).

If it's still jumping around, the enclosure (or drive) may be bad which would make Windows keep losing the connection, though in theory it should just re-assign it the same letter. Does it ever "disappear" for a while and/or do you get a random dialog in Windows that scans your USB device and asks what you'd like to do with it?
posted by teemo at 9:24 PM on February 28, 2007

Verdandi beat me to it. = ]
posted by teemo at 9:25 PM on February 28, 2007

We have this problem regularly with flash drives and external hard drives at work. The source of the problem at work is that folks log into the domain and F, G and H are used by login script as the network share drive letter assignments. If the computer has a floppy, single partition hard drive, and a single optical drive, well, everything is fine. XP assigned A, C and D to those pretty normally.

But if for whatever reason E is taken, by a partition of the hard drive, a second optical drive, or a regular attached external hard drive, XP assigned the flash drive J. Of course, if its an external hard drive causing the problem, that can be disconnected and the flash drive then take E as the drive letter. And the exact opposite can happen.

So, if you are regularly using a flash drive, for example, you may have plugged that in at some point FIRST before you plugged in the external hard drive and then plugged the external hard drive in and... well... bam, hard drive got J.

This can be exacerbated by these loony new "U3" flash drives that create yet ANOTHER drive letter for a CD image for the "clever" software on there that does whatever stupid thing it does (you can download uninstallers, thank god).

It's possible, I suppose, that you had a flash drive attached that had E and then plugged in the hard drive that had J, and for whatever technical reasons I don't know and can't explain that Windows has it socked away somewhere that when it sees your external hard drive now it uses J... but not all the time.

From what I can tell, btw, E and J are the sort of automatic defaults that Windows uses for these externally connected USB and Firewire devices.
posted by smallerdemon at 10:47 PM on February 28, 2007

Response by poster: Thanks, flabdablet, for the info on how to change a drive letter. That will be easier than what I've been doing. To clarify the hardware setup: I'm not using a USB hub. The Seagate is plugged into one of the rear USB ports and doesn't get removed or disconnected. It's just there as a backup device and for storage of any recorded television programs that start to clog up my main hard drive. The other rear USB port has my printer. I have a flash card reader attached to one of the front USB port, and it doesn't get disconnected either. I use the other front USB port for a thumb drive, which obviously does get connected and disconnected. I'm good about using the "remove hardware" icon in the system tray, but sometimes when disconnecting the thumb drive, I get the message that it cannot be "stopped" and to wait and try again, so I just pull it out anyway. I don't need to log in to any network (it's my home computer), and I do have administrator rights.
posted by Joleta at 5:02 AM on March 1, 2007

Best answer: If that flash card reader is one of the ones that supports lots of different formats, it will typically allocate itself a range of consecutive drive letters, one per card slot. If it just so happens that the card reader is awake and ready to go before the external hard drive is (perhaps because the external hard drive is powered down) when Windows starts, then the card reader will "win" and get first crack at the alphabet.

If you use the Disk Management console to specify explicit drive letters for each of the flash card reader's slots, as well as for the Seagate, this should all settle down a bit.

A thumb drive that "can't be stopped" will consume a drive letter until it is properly stopped (perhaps on the next Windows restart). Reefing it out will not fix this; it might even get the next highest letter next time you insert it.

Using the Disk Management console to assign a fixed drive letter to your thumb drive as well might calm this behavior down.

Generally, "cannot be stopped" means that some process is holding a file or folder open on the drive, and is about the riskiest time you could possibly reef out a USB stick. Try to find out who thinks they still need it (close any Explorer windows looking into the drive, close any instance of Word that has had a document open on it, etc) and try the safe removal procedure again. Only go against "cannot be stopped" as a last resort.

Finally, if all you're using the Seagate for is a permanently attached auxiliary drive, you can get at it without any drive letter at all. Provided your internal hard disk is formatted with NTFS, you can create an empty folder on that (say, C:\Backups) and use the Disk Management console to attach the Seagate to that folder (either instead of or as well as giving it a drive letter). Any time the Seagate is plugged in, all its files and folders will then appear to be inside C:\Backups regardless of drive letter shenanigans, and you can just make Memeo go in there.
posted by flabdablet at 7:26 AM on March 1, 2007

Response by poster: Flabdablet: Thanks for all the strategies to try. I'll assign all the slots in the card reader drive letters way down the alphabet, and also assign a drive letter to the Seagate. If that doesn't work, I'll play around with the Disk Management console and setting up a C:\Backups folder for the Seagate.
posted by Joleta at 8:58 AM on March 1, 2007

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