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Drive letters can be manually assigned. In a multiple-machine environment, it will need to be done on each machine.

How can I make an external drive keep its same drive letter?

In this excerpt from Answercast #29, I show how to assign drive letters to portable devices.

External drive letter

Assuming that you're talking about installing it on the same machine repeatedly and have it assigned the same drive letter? In that situation... it's supposed to just work. Windows is supposed to remember the drive letter and give you the same letter again as long as that drive letter isn't now in use by some other piece of equipment.

If that's not happening, the one thing that I would suggest you try is:

  • Go to Drive Manager and assign a drive letter manually: a drive letter of your choice.

In some cases, that seems to have been a little bit stickier in my experience. It seems to do a better job of persisting across the action of the drive being removed from the machine and reinstalled.

Assigning drive letters

I've got an article that will show you how to do that (for Windows XP, at least). It's called, "Can I reassign my drive letters?" It's roughly the same procedure for Windows 7 as well. So it's not hard at all.

That is where I would suggest you go first.

Across multiple computers

Now, if what you're asking is how to assign the same drive letter across multiple machines (in other words, you take this drive from machine to machine, and want it to always have the same drive letter on each one of the machines), there's no automatic way to make that happen that I'm aware of.

The best you can do is use that assigned drive letter functionality on each machine. Assign it the same drive letter and then, presumably, that assignment will persist on each machine. But, you need to go to each machine that you're connecting this thing to and make that assignment manually – to get the same drive letter across all of them.

Next from Answercast 29 – Why don't blocked emails stay blocked?

Article C5513 - June 25, 2012 « »

Leo Leo A. Notenboom has been playing with computers since he was required to take a programming class in 1976. An 18 year career as a programmer at Microsoft soon followed. After "retiring" in 2001, Leo started Ask Leo! in 2003 as a place for answers to common computer and technical questions. More about Leo.

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June 26, 2012 12:18 AM

You can also use the drive manager to assign a folder to mount the drive to. This has the advantage of not using up one of the letters, which can be useful if you have a lot of network shares leaving to many free. The only disadvantage is if a program EXPECTS a removable drive (a la Picasa) it can be confused by this approach.

June 26, 2012 2:45 PM

A frequent problem at a site I support is occasional drive letter misalignment between their backup Software (Norton 360) and the removeable (USB) backup drive. The backup software is configured to backup to drive 'F', but if someone has benn using a memory stick, and maybe downloading pictures from a camera - even if theyse devices have all been disconnected - WinXP sometimes assigns 'G' or even 'H' to the backup drive when it is connected. Needless to say the backup fails.

The solution so far has been to provide the staff with comic book level instructions on how to monitor the backup, and how to assign a new drive number within Norton. I shudder to think what might happen if they start to reassign drives in the Windows file system.

I'd love a better solution, but it must be plug-and-play transparent to the user.

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