Changing Drive Letters

[John Ferrell]

I have several USB drives on my Win7 (32) system. When I swap a drive
into the mix sometimes the Letter assignments change. I am using Sync
Toy for Backups. It requires that the sync pairs be defined by Drive
letter. How can I keep the Letters from changing on Drives I have not
moved?
John Ferrell W8CCW

 

[VanguardLH]

I have several USB drives on my Win7 (32) system. When I swap a drive
into the mix sometimes the Letter assignments change. I am using Sync
Toy for Backups. It requires that the sync pairs be defined by Drive
letter. How can I keep the Letters from changing on Drives I have not
moved?

Windows doesn't guarantee drive letter assignment even if you plug the
device into the same USB port. If you plug a device into a different
USB port, Windows might find the old enumeration data in the registry
that was recorded before so it know what type of device it is and what
driver, if any, to use. You might get the same drive letter but not if
something else already has it. Even plugging into the same USB port
might result in a different driver letter either because the device
requires re-enumeration or another device already has the drive letter.

For forcing drive letter assignment (by the device's enumeration data
whether read in or already recorded), you'll need a 3rd party tool, like
USB Safely Remove: http://safelyremove.com/ ($19.90). Zentimo has a few
more features (see http://zentimo.com/zentimovsusbsr.htm, plus it costs
more) but it's not likely you'll need the extras: http://zentimo.com/
($29.90).

 

[Gene E. Bloch]

I have several USB drives on my Win7 (32) system. When I swap a drive
into the mix sometimes the Letter assignments change. I am using Sync
Toy for Backups. It requires that the sync pairs be defined by Drive
letter. How can I keep the Letters from changing on Drives I have not
moved?
John Ferrell W8CCW

Mount the external drives to an empty Windows folder and refer to that
folder, rather than a drive letter, in SyncToy.

In Disk Management, instead of assigning a drive letter to a drive,
assign a folder name. It must be an empty folder, and it seems better to
use a given folder always for the same drive.

On the other hand - as I think about it, I seem to recall that if you
just assign a drive letter to a given drive, it won't change, as long as
it's high enough in the alphabet to never get automatically assigned to
another drive. And again, don't assign the same letter to different
drives.

Have you been victimized yet by SyncToy's way of dealing with
transitions to and from Daylight Saving Time? Or did they finally fix
it?

 

[Gene E. Bloch]

Mount the external drives to an empty Windows folder and refer to that
folder, rather than a drive letter, in SyncToy.

In Disk Management, instead of assigning a drive letter to a drive,
assign a folder name. It must be an empty folder, and it seems better to
use a given folder always for the same drive.

On the other hand - as I think about it, I seem to recall that if you
just assign a drive letter to a given drive, it won't change, as long as
it's high enough in the alphabet to never get automatically assigned to
another drive. And again, don't assign the same letter to different
drives.

Have you been victimized yet by SyncToy's way of dealing with
transitions to and from Daylight Saving Time? Or did they finally fix
it?

BTW, be sure to exclude from your backup the folder name you use for
mounting

 

[Dave \Crash\ Dummy]

I have several USB drives on my Win7 (32) system. When I swap a drive
into the mix sometimes the Letter assignments change. I am using
Sync Toy for Backups. It requires that the sync pairs be defined by
Drive letter. How can I keep the Letters from changing on Drives I
have not moved? John Ferrell W8CCW

Use Disk Management to assign specific drive letters to your USB
devices, preferably letters above the current sequence, like P,Q,R or
X,Y,Z. You can even assign different drive letters to different devices
using the same USB port.

 

[Stan Brown]

I have several USB drives on my Win7 (32) system. When I swap a drive
into the mix sometimes the Letter assignments change. I am using Sync
Toy for Backups. It requires that the sync pairs be defined by Drive
letter. How can I keep the Letters from changing on Drives I have not
moved?
John Ferrell W8CCW

Insert the USB drives, then open Disk Management: click the start
button and then type diskmgmt.msc, or go into Control Panel: Change
Drive Letters and Paths.

A display will show your current drives. Right-click the first one
you want to assign, and change its letter. Repeat for the others.

 

[Stan Brown]

For forcing drive letter assignment (by the device's enumeration data
whether read in or already recorded), you'll need a 3rd party tool, like
USB Safely Remove: http://safelyremove.com/ ($19.90).

In my experience, no third-party tool is required. Windows does not
automatically use the same letter every time for the same device, but
when I assign a letter to a device once, Windows remembers it for all
future connections of that device.

 

[Steve Hayes]

I have several USB drives on my Win7 (32) system. When I swap a drive
into the mix sometimes the Letter assignments change. I am using Sync
Toy for Backups. It requires that the sync pairs be defined by Drive
letter. How can I keep the Letters from changing on Drives I have not
moved?

If you give it a drive letter immediately after your non-removable frives, it
should remain the same.

I have an external hard drive that is K:, and I tryo to set USB flash drives
as J:, but sometimes need to reset them by running:

diskmgmt.msc

 

[pjp]

If you give it a drive letter immediately after your non-removable frives, it
should remain the same.

I have an external hard drive that is K:, and I tryo to set USB flash drives
as J:, but sometimes need to reset them by running:

diskmgmt.msc

I use a lot of removable devices. I often have a card reader, 3 external
hard drives and a couple of flashdrives all connected at same time.

What I've found is once you set a device to use a specific drive letter
it'll keep using that drive letter provided the device is always
connected to the same port.

I give everything a volume label unique to what it is.

I have as real devices drive c & d (both hard disks) and e, f & g as
burners (g is virtual burner). They remain constant on every boot.

I have one external drive labelled Expansion never gets turned off even
during reboots. I set it up as drive S and it's always stayed that way.
The two other external drives always come up as O & Q. Again setup that
way. All these hd's connect thru a USB self-powered hub so are always
using the same port.

The card reader is always W, X, Y & Z. This stays provided I plug the
reader into the same usb port.

The flashdrives are always I, J, K or L depending on which flashdrive
I'm using and also provided it's pluged into same port as usual.

If I plug in any device to a different port than normal it's seen as
drive H (next available drive letter). Same with any new device system
hasn't seen before.

Any networked drive I set to N and seldom map more than one at any time.

 

[Dave \Crash\ Dummy]

I use a lot of removable devices. I often have a card reader, 3
external hard drives and a couple of flashdrives all connected at
same time.

What I've found is once you set a device to use a specific drive
letter it'll keep using that drive letter provided the device is
always connected to the same port.

In my experience, they don't even have to be connected to the same
port. The drive letter is retained no matter which port I use.

 

[VanguardLH]

In my experience, no third-party tool is required. Windows does not
automatically use the same letter every time for the same device, but
when I assign a letter to a device once, Windows remembers it for all
future connections of that device.

And yet I have seen, almost every couple of cold boots, where a USB
dongle will have its drive letter changed. I'll assign it "M" (which is
above anything else that gets assigned). There is no other removable
media (USB or other devices) getting assigned drive letters above "E".
Yet, after a a couple cold boots, that dongle might end up getting
assigned the next drive letter available (which is "E" since "D" is the
last one for a hard disk). This screws up my backups wanting to use
drive E. I hide a third hard disk by not assigning it a drive letter
until the backup job runs. The backup job has a pre-command function so
I use diskpart to assign the drive letter before the backup, run the
backup (which expects to save to drive E), and remove the drive letter
after the backup completes. Because the dongle gets assigned "E" (when
the backup isn't running), and because its software expects to find "M",
I have to reassign the dongle to "M" to get its software to recognize it
again. If the software fails to find the device (which happens on a
cold reboot) then I know that I have to go change its drive letter ...
again ... and rerun the software. This is one of the reasons why I
leave my computer powered on all the time.

In violation of the USB specifications, some USB devices have no serial
number to clearly differentiate themselves. That means when you plug it
into a different USB port, Windows won't know if it is the same or
different device as already enumerated in the registry hence the change
in drive letters.

The trick of assigning a drive letter way down the list, like starting
from "Z" and progressing backward, often works but not always. That
trick sticks the drive letter assignment for awhile but it isn't
permanent. If you want to *guarantee* the device gets assigned the same
drive letter then you need a drive letter manager that interogates the
presentation data (or enumeration data if already recorded in the
registry) from the device to clearly identify it.

If you don't like the idea of having to pay for a program with tons of
features (that you may not want or may not use) and just want something
that fixes the drive letters based on their enumeration data then look
at:

USB Drive Letter Manager
http://www.uwe-sieber.de/usbdlm_e.html

It's freeware (for private and school use only). As I recall, it
harkens back to the olden days when you edited an .ini file to configure
the program instead of using a pretty GUI. It runs, I believe, as an NT
service so it loads before you even login.

 

[SC Tom]

In my experience, they don't even have to be connected to the same
port. The drive letter is retained no matter which port I use.

I have two USB drives that I use for saving my backup images, one lettered W: and the other X:. I named them in WinXP,
and when I plug them into my Win7 laptop, they retain the same drive letters. So not only does it work across ports, it
also works across PC's and OS. (or at least it does for me )

 

[John Ferrell]

Have you been victimized yet by SyncToy's way of dealing with
transitions to and from Daylight Saving Time? Or did they finally fix
it?

Uh Oh!
Please tell me more... I was just getting comfortable!
John Ferrell W8CCW

 

[Stan Brown]

[quoted text muted]
into the mix sometimes the Letter assignments change. I am using Sync
Toy for Backups. It requires that the sync pairs be defined by Drive
letter. How can I keep the Letters from changing on Drives I have not
moved?

If you give it a drive letter immediately after your non-removable frives, it
should remain the same.

It doesn't even have to be immediately after. I have Z: for my
CD/DVD drive, and K: for my USB stick, and it has *never* come up as
anything but K:, in over two years on Win 7 Enterprise and Win 7 Home
Premium (home and work computers).

 

[Stan Brown]

What I've found is once you set a device to use a specific drive letter
it'll keep using that drive letter provided the device is always
connected to the same port.

I've found it's not necessary to connect to the same port.

 

[Stan Brown]

Uh Oh!
Please tell me more... I was just getting comfortable!
John Ferrell W8CCW

I don't think that's SyncToy, I think it's Windows. NTFS file
systems seem to have file times recorded in UTC; FAT32 file systems
seem to have file times recorded in local time. So when daylight
saving time begins or ends, files that were in sync between my hard
drive and my USB stick are now an hour out of sync. And I use the
command-line command REPLACE /U.

 

[Dave \Crash\ Dummy]

I have two USB drives that I use for saving my backup images, one
lettered W: and the other X:. I named them in WinXP, and when I plug
them into my Win7 laptop, they retain the same drive letters. So not
only does it work across ports, it also works across PC's and OS.
(or at least it does for me )

Thanks! I wondered about that. I only have one computer, so it would
take a trip to the library for me to try it.

 

[Steve Hayes]

[quoted text muted]
into the mix sometimes the Letter assignments change. I am using Sync
Toy for Backups. It requires that the sync pairs be defined by Drive
letter. How can I keep the Letters from changing on Drives I have not
moved?

If you give it a drive letter immediately after your non-removable frives, it
should remain the same.

It doesn't even have to be immediately after. I have Z: for my
CD/DVD drive, and K: for my USB stick, and it has *never* come up as
anything but K:, in over two years on Win 7 Enterprise and Win 7 Home
Premium (home and work computers).

Perhaps it's an XP problem then.

I use USB flash drives to copy files from my desktop PC running Windows XP and
my laptop running Win7.

On my old desktop, There were two hard drives, the second split into D: E: F:
and G: partitions, and two DVD drives, H: and I:

I had Linux installed on the D: partition.

Then my computer died, and I bought another with two hard drives, but only one
DVD drive.

I restored all the Windows partitions from backups (Acronis), but had to
reinstal Linux on the D: partition from scratch. Now Windows does not
recognise that as a partition, so when I insert as USB flash drive it
registers as D:

I change it to J:, and all works well for a week, when I switch to my other
flash drive, which then becomes D: and I change it to J:

I need to to this because the batch file that refers to the flash drive refers
to J.

But on the Win 7 machine it's usually F:, unless, of course, there's something
else inserted. But I always do my transfers right after turning the machine
on, so that's OK.

 

[Paul]

[quoted text muted]
into the mix sometimes the Letter assignments change. I am using Sync
Toy for Backups. It requires that the sync pairs be defined by Drive
letter. How can I keep the Letters from changing on Drives I have not
moved?
If you give it a drive letter immediately after your non-removable frives, it
should remain the same.

It doesn't even have to be immediately after. I have Z: for my
CD/DVD drive, and K: for my USB stick, and it has *never* come up as
anything but K:, in over two years on Win 7 Enterprise and Win 7 Home
Premium (home and work computers).

Perhaps it's an XP problem then.

I use USB flash drives to copy files from my desktop PC running Windows XP and
my laptop running Win7.

On my old desktop, There were two hard drives, the second split into D: E: F:
and G: partitions, and two DVD drives, H: and I:

I had Linux installed on the D: partition.

Then my computer died, and I bought another with two hard drives, but only one
DVD drive.

I restored all the Windows partitions from backups (Acronis), but had to
reinstal Linux on the D: partition from scratch. Now Windows does not
recognise that as a partition, so when I insert as USB flash drive it
registers as D:

I change it to J:, and all works well for a week, when I switch to my other
flash drive, which then becomes D: and I change it to J:

I need to to this because the batch file that refers to the flash drive refers
to J.

But on the Win 7 machine it's usually F:, unless, of course, there's something
else inserted. But I always do my transfers right after turning the machine
on, so that's OK.

Uwe has a few tools. For example, Drive Letter Manager (USBDLM)

http://www.uwe-sieber.de/usbdlm461_help_e.html

He has more tools here.

http://www.uwe-sieber.de/drivetools_e.html

Paul

 

[Gene E. Bloch]

Uh Oh!
Please tell me more... I was just getting comfortable!
John Ferrell W8CCW

SyncToy doesn't have a way of understanding the effect of daylight
saving time changes on file creation or modification times (as explained
by Stan Brown in his reply).

The result is that when DST is turned on or off, SyncToy sees the
one-hour change, and so it copies all of the files (that were changed
during the prior state of DST) from one device to the other, and the
reverse happens at the next switch.

But I was careless, and Stan's information will help you realize that
the problem exists when of one of the file systems is FAT and the other
NTFS (or more generally, when one file system uses local time and the
other uses UTC time).

I can imagine that there might also be a problem if both systems use
local time, but after my afternoon coffee I'll surely realize my error
in thinking that

BTW, the main reason for this is that am syncing form such things as
camera or telephone SD cards to backup folders on my hard drive, and the
SD cars are formatted FATxx. This is required by the devices that use
the cards.

Anyway, Allway Sync understands - actually, assumes - that time
differences of exactly one hour (or sometimes an integral multiple of
one hour, if you travel between time zones) aren't really different.