Helping people with computers... one answer at a time.

Drive letters, like C:, D: and so on are assigned by Windows to reference your hard disks. They are not cast in stone: drive letters can be changed.

I have 2 hard disc drives and a cd rom drive on my computer. The HDDs are C and E, and the cd rom drive is D. Is it possible to swap the HDD letters, i.e C becomes E and E becomes C? Or are the letters fixed at the time of format?

Drive letters are not assigned at format time, and yes, they can be changed. In fact, it's quite easy to change them, and I do it all the time.

For every drive except "C:", that is. "C:" is special.

First let's look at the how.

The utility we want to run to manage our disk drives is, surprisingly enough, the disk manager.

Right click on My Computer and click on Manage and you should see something very much like this:

Computer Management Dialog

Now, click on Disk Management, and you should see something like this (You may need to resize the window larger, as I have, in order to see everything):

Disk Management Dialog

You'll see that I have several disks listed ... C: is my system drive, E: is my external USB/Firewire backup drive, F: and G: are drives representing the slots in a small 8-in-1 memory card reader. Off the screen also is D:, my DVD/CD drive.

To change the drive letter assigned to a drive, right click on the drive in disk manager. For example here I've right clicked on my E: drive:

Right click on E:

Click on Change Drive Letter and Paths... and you'll get this dialog:

Change Drive Letter and Paths... for E:

You can guess where this is headed by now ... click on he Change... button for this dialog:

Change Drive Letter

In the picture above I've already clicked on the dropdown list that will allow me to select which of the available drive letters I want to assign.

"I don't recommend that you ever use the disk management tool to try to rename C:."

Since you can only assign to unused drive letters, swapping is a three step process. Say we wanted to swap D: and E: -

  1. assign the disk known as D: to any unused letter, say Z:, which frees up D:.

  2. assign the disk known as E: to D:, which frees up E:.

  3. assign the disk now known as Z: to E:, and you're done.

An important word about C:

I don't recommend that you ever use the disk management tool to try to rename C:. C: is, most likely, where Windows is installed, and Windows will not respond well at all to the drive letter being changed out from underneath it.

There's also a good chance that this will not do what you want anyway. The Disk Management utility only affects how Windows looks at the drives - it won't change which drive you boot from, since booting happens before Windows has access to this information.

While there are utilities out there to move things around, changing your boot drive is best and most reliably done before you install Windows. That way the drive you want to be C: is color: from the start, and Windows is installed to it from the beginning. My approach to changing the boot drive on a running machine would be just that - I'd wait until I was going to reinstall Windows for some other reason, and do it at that time.

Exactly how you change your boot drive is typically either a BIOS setting, a disk drive jumper setting, or a combination of both. In any case, it's specific to the machine you have and the drives you happen to have installed.

Article C2743 - August 4, 2006 « »

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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.

Not what you needed?

August 4, 2006 10:26 PM

I partition my 300gb drive and have got to n:/ so far. To avoid problems if I increase/reduce partitions I reserve x,y and z for cd and dvd. Sometimes if you change these and try to run a programme installed when the drive letter was F:/ there can be a problem.

August 13, 2006 1:57 PM

How easy was that! - Well done it worked and I have no further problems - Thanks Leo

September 25, 2006 1:47 PM

My drive letters are inverted C and D, so my computer looks through my D drive which it thinks is C to get to C which is marked as D, how can I fix this?

October 18, 2006 5:39 AM

How brilliant are you! How brilliant is knowledge! I have just spent 4 1/2 hours on the net and speaking to computer buffs searching for the answer to change drive letters (too complicated to explain why). CANNOT BE DONE - CHANGE THE BIOS - ALTER JUMPERS etc. etc. You managed it in under 2 minutes!!! (After I found you)You are wasted and should be as accesable as a screwdriver. You are now No1 Bookmark
Kindest regards

PJ Baron
November 8, 2006 10:06 AM

I just installed a 1X2 TX RAID system using RAID 1 for mirroring. Went I went to install windows it had my drives assigned to J: for the root!
Now using disk management under XP told me that I could not reassign the Windows Root Drive (J:)
How do I do this without reinstalling windows?

PJ Baron

January 3, 2007 2:09 PM

Oh my i'm so glad that i found you. I have spent 4 days tring to find out why my computer seen my flash drive but didnt show up when i went to my computer. well to keep it short my dvd drive and my flash drive had the same letter so i plugged in my flash drive and did just what you told me and now it works fine thank you ever so much...

February 8, 2007 9:38 AM

That was great help..........

February 13, 2007 1:33 AM

Thanks you soooo much. I have been strugeling to find a easy to understand explination for 5 days now, your pictures and explinations are awesome. Thanks very much

Miles Nitz
February 14, 2007 8:09 AM

I have the same problem as the question on your website --- My drive letters are inverted C and D, so my computer looks through my D drive which it thinks is C to get to C which is marked as D, how can I fix this? (Posted by Sheila, 9-25-06) Were you able to answer this?

Mike French
February 19, 2007 1:13 PM

Dude. Thanks for the drive switcheroo help. I never knew this stuff and I really appreciate your help, and all the hard work that you put into this site. But, it shouldn't be called "Ask Leo." You could name it something comical like "Ask Beardo." That would be more memorable and funnier. Beards are awesome to the max.

March 5, 2007 2:58 PM

This info was helpful but I'm still having a problem with reassigning the drive letter. For some reason when I installed XP it named my boot drive F: and my second drive C:. Before the change in operatiing systems they were boot: C:, and the second was D:Storage.
It let me change my storage drive letter, but won't let me change my boot drive from F to C.
Any suggestions?

Leo Notenboom
March 5, 2007 8:01 PM

Hash: SHA1

Did you read the article? It explicitly talks about exactly that.

Version: GnuPG v1.4.6 (MingW32)


William S
March 14, 2007 6:54 PM

I appreciate it Leo. You've made something that most people make out to be a four hour expedition through cmd a 20 second switch. You are now bookmarked bro.

Jerry McCormick
March 21, 2007 1:52 PM

But my system always forgets the new drive letter assignments on my CDROM & CDRW drives. Everytime I boot up, the drive letters have changed back to the first available letters above my HDDs' partitions. To match my older computer's CDROM & CDRW drives' letters V: and T:, I have done the disk management drive letter change routine over and over, but each time I reboot these two drive come back as M: & N:. Additionally, Roxio's (EMC8) drag-to-disk will not let you change the non-existent M: to T: so that I can use it to eject, format, etc. It holds on to the erroneous M: even though no M: exists resulting in a rediculous message such as "Drive is Busy" when I try to use it to eject a CDRW. EMC8 "Home" properly shows the CDRW drive as T: but apparently Drag To Disk checks only during it's startup process and retains what it found at startup -- the erroneous M:. Help!

April 7, 2007 9:08 PM

I reassign drive letters to the way i need them. then everytime i reboot they change back??? why???
I just installed new raid sata hard drive. My raptor which has 200 gigs of info and audio/video session files on it needs to be set at drive D!! for some reason the dvd drive wants that letter evrytime i reboot??? help please!!???

Kenneth Bloom
April 16, 2007 3:13 PM

HI, I had to reistall my DVD on the "F" drive, and now its missing. Now I only have the "G" drive . Is there anything I can do?

Sincerly Kenny P.S I read the letters above but I don't understand it too well.

May 16, 2007 11:49 AM

What about the A: (floppy) drive. I have a computer that is only for use with a particular program. In the program it asked to "backup" and dose so on a floppy. It takes forever. If I could assign the USP card as the a: it would make things so much easier.

June 13, 2007 2:46 PM

thanks Leo and all those great people posting helpful information on the internet! Always amazed how easy it is to find info ... thanks to those that devote time to helping others!

Andrew Lockhart
August 15, 2007 4:05 PM

I have a simular problem... except I have 3 drives in my pc. 1st one is an older ata and the other 2 are newer sata drives. when I re-installed windows it assigned my drives as follows:
c: is the older ata
d: is the first sata
e: is the second sata
Now here is my problem.
When Windows was installed it went on to the D: drive but C: is my boot drive. All the boot files are on that drive and not on the other two. I would like to remove my C: as it is getting older and does not sound that good.

There is currently nothing on either my C: (except the boot files) and E: drive.
I have tried to copy the boot files over to E: and removed C: and swapped the cables around but it still will not boot up.

Is there any way I can swap my C: and D: or C: and E: as I really want to remove my old drive before it fails???

CJ Parker
October 4, 2007 8:02 PM

I agree with Mike French. The site should be called
"Ask Beardo" because it makes so much more sense and would be funnier than just boring "Ask Leo". Thanks for the info!

Christina Nation
October 19, 2007 6:37 PM

I freakkin LOVE YOU!

My external one day just went from G to N.

Dunno why. It irritated me to know end.
And, because that's one of my photo storage units the Lightroom has assigned to it's backups and databases...I was looking at a heap of crappy, crappy trouble.

You have saved my A$$.

Thank you again,


Colin Hudson
October 24, 2007 8:01 AM

Help !!!!

I have an external drive which I back up to daily came to back up files and 2 things, the drive id has changed to F: and it states its full and do I want to format it...obviousley NO.

I thought if I renamed it to its previous drive letter in this case G:it would recognise the path and my files would be there, wrong so I have a drive that has heaps of data on it yet it shows it as full disc with no bytes and I cant read it.

Please can you help and advise what I need to do.

Many Thanks
Colin Hudson

November 17, 2007 11:19 PM

I tried reassignment but only got letters to change that are after the two that are missing.I have HP M370n Media Center.My Dvd writer Cd writer combo wont recognize cds /Mp3s that I recorded on it and shows up at 0 bytes like nothing is on it but there is.Also both my combo player/record and my other HP CD writer that I installed myself after the factory CD rom player quit has reassigned what was formerly E: 300n and F:HP 8000n to G:compactflashI/II - Cd Drive and H: smart media nad has the icons of both by them yet my smart media and compact flash is still L: and M: I cant figure out how to switch them back with icons and make them E and F again.I tried your method but it wont let me change to E or F as those letters seem to be missing.Any clues?Also I cant find updated drivers for 300n.

December 7, 2007 11:41 AM

I bought a new Toshiba notebook, in order to run some of the old software.. I had to partition the HDD with a D: drive.. so, as required.. I had changed the CD ROM drive to E: drive.. after few days of struggle, everything is working.. all in a sudden.. I lost my E: drive?? now I have removed D: drive.. I mean removed the whole partition.. but I still can't see my CD ROM drive.. it is really frustrating.. anyone had this experience.. any solution?
thanks for all your help.

Jerry McCormick
December 11, 2007 1:46 PM

My problems that I posted on March 17, 2007 seem to have finally resolved themselves. My personally assigned drive letter T: for the CDRW & V: for the read only CD player seem to be staying that way between boots now. Must have been corrected in a Microsoft update or something.

Jerry McCormick
December 11, 2007 1:49 PM

Wrong date for previous posting. I typed March 17th where I should have said "posted on March 21, 2007"

December 19, 2007 9:00 PM

Good Job worked great.

December 27, 2007 2:54 AM

Many thank, you have been a great help. Pesky computers!!!

Josh Campbell
January 2, 2008 4:46 PM

Thankyou very much, that's exactly what i needed to do.

March 16, 2008 1:48 PM

ok i got a dell 1100 inspiron won't read dvd/cd rom i tryed updating driver, roll back,and last but not least changing the drive letter. i was thinking unstilling the software and redownloading from dell s website u got any other methods i could try???

mathew davies
July 31, 2008 10:59 PM

hi i have an ifriends computer and i just installed a super multi dvd rewriter but now its sayin cd drive file system unknown and i have zero bytes on my drive d im not to good with computers so im kind of stuck is there something i have dones wrong please help if u can thanks!!

David Clark
August 11, 2008 7:39 AM

What a brill web site. After days of worrying your answers solved my problem in minutes.

September 30, 2008 12:27 PM

Thanks! This help tool came in VERY handy!

Sheri Zampelli
October 7, 2008 8:58 AM

This is just what I needed to know. Thank you.

Eddi Lowe
November 27, 2008 7:17 AM

I found this article ages ago and it was very useful at the time but I never commented. I've searched for the page again because I had a friend with the same issue I had originally and this page easily explained how to change the drive letter with screen shots etc which is really helpful.

Originally I'd been trying to access some files on my USB memory stick and it wouldn't show up in "my computer" so I searched for why this would happen and because I already had a mapped network drive with the same letter I now know that it will only recognise one drive with that letter at a time... the page in question (no idea what page it was specifically) said change the drive letter assigned to it but didn't tell me how. This page did :o)

December 3, 2008 9:25 PM

Hi.. I want to install Windows XP on my 80GB external HardDisk..Pls suggest me proper steps for same..also I came to know that even if I do it, the OS when booted frm HDD will be very it will use processor from PC!! Is it the case ??

December 24, 2008 9:55 PM

hi leo, i have recently been attacted by a worm called 'silly dc'it changes the drive paths of the c and d drives i think i have cleaned it all up, but i am still getting a reference to ' resycled\boot' as the path for the c and d drive how do i change that??? thanks in advance
ps im using xp pro with service pack 1

Brian Clark
January 11, 2009 2:06 PM

Your directions to change drive letters is very easy to carry out. I have a problem because my
D: drive is shown as (Z)(D) I would like to get rid of the (Z). I am not sure wether to follow what you say or wether I would have problems
I have sbsribed to your site and am waiting for the email Thanks for a very good site...Brian

January 27, 2009 3:37 AM

Does not work in my case. I have G: drive and want to change it to D:, it does change my letter but after the boot the paths are the same linked to G so all my programs installed on G: are unaccesible.

gt morgan
August 4, 2009 8:30 PM


November 13, 2009 4:43 PM

Thanks, this works on Windows 7.

Very easy to do. Who knew.

January 4, 2010 5:23 PM

I installed a new c drive but it came up as H How can i get it to C ? I unhooked My card reader and my burner rebooted still comes up as H.What can I do ?

February 15, 2010 12:19 PM

Thanks man! My CD drive came up as Z! Without any drives between it! Strange... But fixed now!

P.S. It really works on Windows 7!

February 27, 2010 8:38 AM

I wiped my hard drive to re-install windows XP. When installing it used the "H" as my system drive. Can I change this to "C" without problems, or without removing windows and starting over?
When patitioning the drive, it showed other drives, but it wouldn't let me delete them. This is my 1st time installing windows.

You'd best reinstall. The problem is that the "H:" is most likely saved in so many different places that you wouldn't be able to find and change them all.

Mike Perera
March 4, 2010 11:12 AM

Great article, you helped fix a minor emergency. Thanks very much.

Kevin W.
March 25, 2010 6:00 AM

Here’s my situation; I have a MA7 Laptop with no operating system on it. It has a DVD/CD ROM and (4) USB ports and can be configured to boot via a USB port, however when I use XP Pro in the DVD drive to load the OS it says ‘no hard drive detected. After some research, I found out that it need’s the hard drive driver(s) loaded prior to loading the OS via the F6 key during the OS installation in order to ‘see’ the hard drive.

I have another computer with a floppy drive (A: drive) and I can extract the files, but the laptop I’m trying to load the OS on has ‘no floppy drive’. So my question is, Can I reassign a USB port as (A: drive) in order to, one, extract the hard drive drivers file to and two, can I write some sort of DOS line code in a AUTOEXEC.BAT/CONFIG.SYS file on the USB Flash drive to ‘fool’ the computer in to thinking the USB is a floppy drive to access the hard drive driver files in order to load the operating system?

Any help would be greatly appreciated.

Kind regards, Kevin in Cleveland, Ohio

Jim Z
April 20, 2010 9:57 AM

I have multiple drives mapped, and it looks like I accidentally remapped the e: (my CD drive) to a file server. I have disconnected e:/ drive, but I still cannot see the CD drive to relabel it. Help.

Reboot, and see if that resolves it.

Jess L
May 3, 2010 4:44 PM

After selecting a new drive letter for my external hard drive (I want P instead), I get an error message that says "The parameter is incorrect." Any ideas why?

Jess L
May 4, 2010 9:16 PM

To clarify, I'm on a brand spankin' new Asus laptop with Windows 7, and just about the only thing I've done is plug in my external hard drive and load Picasa. (I need the drive to stay the same letter for Picasa.) The laptop says the drive is D: for that external hard drive, and I'm I'm used to D being an important internal hard drive but I'm not sure how this laptop's set up. Could that be why selecting P doesn't work? (And I tried Z and it doesn't work either.)

Jess L
May 10, 2010 7:50 PM

It turns out that I can use M, just not P or Z or Q. Strange. But M works, so I'm going with it! Thanks for this helpful article.

David s
March 17, 2011 10:36 AM

my h drive has been relabelled j but when i go to the drop down box in disk management it opffers me a,b then from j onwards... why has it skipped H ? i need to relabel it im [ID deleted] on twitter thanks

April 28, 2011 9:02 PM

Thank you Leo. You have saved me so much fruitless messing around on my machine to keep my portable hard drive with F assigned. Thank you, your advice was absolutely spot on.

August 18, 2011 8:21 AM

My computer detects the dvd and the cd as different units, and they are the same. One as F and the other as Z but i need to use z as a network connection. The problem is that i can only see the dvd drive in disk management so i can only change the F. How can i change the letter of the Z cd drive?

September 11, 2011 1:08 AM

i had windows vista in my laptop.i put out the internal hard disc and i made to it a format with a docking stasion.the problem now is that i cant give the letter c again in this disc because its allready on the lap top that the docking stasion was i am tyrying to run windows with thios hdd and they stop and message telling me that is not any hdd in the lap top

September 22, 2011 6:02 PM

Hey, I already passed the point where I can stop. Your warning re C:\ drive should be stated early in the document!

mike mattice
September 29, 2011 10:48 AM

Thanks Leo you just saved me a lot of hours

October 7, 2011 6:18 AM

Brilliant straight forward answer. Saved hours of frustration trying to reset drive letters. Thanks Leo.

October 17, 2011 9:45 PM

Thanks so much, Leo. I have 3 EHDs and my categories in ACDSee are assigned to one of these so when the letters changed, I lost my ability to go to those searched files. Great tutorial! You're wonderful!
PS: I always read through my recipes before starting to make sure I have everything I need. Sorry Cyberpilot. I hope nothing drastic happened.

October 28, 2011 12:33 AM

my c drive is 1.95gb and my d drive is 35.3 thats how much they can hold not how much free storage there is and my pc is crapping out! please help, {email address removed}

Mark J
October 28, 2011 12:49 AM

You might be able to combine the 2 partitions into one with a partitioning utility

November 6, 2012 2:58 PM

Thanks, Leo.

Daniel from Czech Republic
January 4, 2013 10:21 PM

Thanks Loe work for windows 8 is well.

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