View Full Version : how to assign letters to (USB) drivers?

Ethan Morlox
03-16-2004, 07:35 PM

I have a problem with my external devices, the letters which are given to them:

At first, I connected a Flash USB drive which had letters B and F (knowing that A, C, D, E, G, I, J, K, L, M & N are used). B: is a default setting apparently.

I added another USB device, which should have taken the H: letter (as the next available) but instead, it chose F: and gave H: for the Flash USB drive! How come?

Worse, I have a third USB device which is apparently connected (works normally) but without any letter given! In other words, I can't access it...

What can I do?

And by the way, isn't there any possibility to have B: available as a normal drive? (I want to set up a DVD burner and all the next letters will be unavailable) Surely it must be possible!


03-17-2004, 02:34 AM
First of: Welcome to The PC Guide! :)

I don't think it is possible to use the "B" designation for any drive, other then your secondary floppy-drive (which not that many people have anymore these days :) ).

Also: In my experience using WinXp, the os tends to jostle around the driveletters for all non-fixed drivers, meaning: your partitions have fixed drive letters, but that's it. On startup windows will re-assign driveletters starting with the "a" for the floppy and then the first free letter after "b" for all non-harddisk-drives (cdroms, dvds, usb-sticks, zipdrives, ...) Since it always deals them in the same order, the same letters always end up with the same drives untill you add something.

So as to your question: "what can I do" my answer would by: role with the punches, curse at MS and move on :( (unless greater minds here on the forum know of a solution of course ;) )

Paul Komski
03-17-2004, 07:10 PM
<marquee direction="right" scrollamount="6"><font face="Comic Sans MS" color="blue"><b>... Ethan Morlox - Welcome ...</b></font></marquee>

Presumably this is Win2K or WinXP and if so the drive letters can be assigned/reassigned from DiskManagement (reached by entering diskmgmt.msc in the Run Box).

All drive letter can be reassigned in Win2K/XP (except for the system and boot partitions) and this includes A and B, which are normally reserved for floppy drives and which would get A and B by default.

The OSes remember the settings in the registry and can usually recognise the physical drives/partitions individually because when formatted they are given a unique ID signature written into the boot sectors. Possibly this is different for flash drives or maybe the drive was formatted at some point.

A number of these drives are partitioned into a 1.4MB floppy-emulation as well as another hdd-emulation partition, so that if the bios supports and recognises these, the floppy partition can be used as if it were an EBD.

Win2K/XP use a number of related methods to assign drive letters intelligently and logically at boot-up time. However if one is constantly changing the non-fixed disks it would be surprising if some confusion did not ever occur - though it should be possible to rectify things with a bit of "disk letter management". ;)