USB Flash Drive Woes

[2techs]

I work for a school district and we are having problems using USB
drives (flash drives, cameras etc). After inserting a flash drive a
number of times in the computer, mapped drives will disappear. Or the
flash drive doesn't show up. I've read how to assign the flash drive a
drive letter, but that doesn't work because of different students using
different kinds of flash drives. Plus they use different USB ports.
Nothing is the same. I've tried using "devcon" to delete usb vid
devices, but since there are a number of different flash drives that
are used, this wouldn't work out. There are different types of
computers being used, one has a USB media drive that has 4 mass storage
devices. Nothing I've tried seems to work, consistantly.

I believe part of the problem occurs because of the way the USB device
is uninstalled incorrectly and that leaves hidden drives. If these
hidden drives collide with a mapped drive, the mapped drive disappears.
Is there anything that I can do to always delete the "hidden" drives
on shutdown? Or am I totally missing something obvious? I've been
doing a lot of research, but have come up empty.

Any help you can give is GREATLY appreciated! Thanks!

 

[R. McCarty]

Map your drives to Z,X,W...this will leave room for USB Thumb drives
to take ascending drive letters. Also buy USB extension cables and have
students use that as their "Only" access port to avoid re-enumeration &
not Pick-&-Choose a USB socket to access.

 

[kpelinski]

Thanks for the reply. We cannot remap the network drives. Our
district drive mappings start with H:\ and go to Y:\ in some cases.
Not all the drives inbetween H and Y are used however. Wouldn't there
be the same issue with a USB extension cable? I can put one thumb
drive on the system and get drive F:\. Everytime I put that same thumb
drive in the computer, I will get F:\. If I put different thumb drive
in the system, I will get drive G:\. If I put another different thumb
drive on, I will get H:\ drive. This pattern will continue as I put in
different thumb drives. If the H:\ drive is mapped to the users Home
directory, the user will not see the H:\ drive or the thumb drive. Is
there a way to stop emumeration?

 

[Uwe Sieber]

Thanks for the reply. We cannot remap the network drives. Our
district drive mappings start with H:\ and go to Y:\ in some cases.
Not all the drives inbetween H and Y are used however. Wouldn't there
be the same issue with a USB extension cable? I can put one thumb
drive on the system and get drive F:\. Everytime I put that same thumb
drive in the computer, I will get F:\. If I put different thumb drive
in the system, I will get drive G:\. If I put another different thumb
drive on, I will get H:\ drive. This pattern will continue as I put in
different thumb drives.

I know this ascending letter assignment only if the drives
are attached at the same time. Otherwise the first free
local letter is assigned by default.

To overrule the default letter assignment I wrote a little
Windows service - the USB drive letter manager.
http://www.uwe-sieber.de/usbdlm_e.html

With the current release you can define a new list of
default letters. If your network shares are static,
you can put all you unused letters to the list. You
can use B:\ too which is often free.

With the next release you can define static letter for
each USB port. But it's a bit hard to configure if you
have to admin lots of computers with different hardware...


Greetings from Germany

Uwe

 

[kpelinski]

Uwe,

You are a genius. This is fantastic! Thank you so much.

I've installed it and I'm in the process of testing. I've put B, F and
G in the USBDLM.ini file, under Drive Letters. Each flash drive I've
put in the computer grabs one of those three letters. But, the only
drive that can actually be seen is the B: drive. The other two drives,
F and G, are installed, but are not visible. Have you come across this?

 

[Uwe Sieber]

I've installed it and I'm in the process of testing. I've put B, F and
G in the USBDLM.ini file, under Drive Letters. Each flash drive I've
put in the computer grabs one of those three letters. But, the only
drive that can actually be seen is the B: drive. The other two drives,
F and G, are installed, but are not visible. Have you come across this?

What exactely means 'installed but not visible'?

The letters has been unused and when you attach the second
drive it gets F but it's not accessible?

 

[kpelinski]

Correct. I see the first drive I've put in, which comes up as B:\.
With the first drive still in the computer, I put in a second drive, a
message comes up and states new hardware found and ready to use but I
cannot see the drive. I put in a third drive, the computer knows there
is another drive, but again, I cannot see it. I can only see B:\, not
F:\ or G:\, when three drives are inserted in the computer.

 

[Doug]

That is STRANGE. I have had very little trouble with Flash
drives. I even transferred files from one drive to the udder one
with NO problems.

Did you ever try to send files to the drive that you can't SEE?

What kind of computer?

So many questions...so few answers.

DRW

 

[kpelinski]

Yes, I tried to send files to a drive that I couldn't see and the
computer complained about it. Go Figure! The computers in question
are: Hewlet Packard DC7600 High End computers.

 

[Bob I]

What shows up in Disk Management?

 

[Uwe Sieber]

Correct. I see the first drive I've put in, which comes up as B:\.
With the first drive still in the computer, I put in a second drive, a
message comes up and states new hardware found and ready to use but I
cannot see the drive. I put in a third drive, the computer knows there
is another drive, but again, I cannot see it. I can only see B:\, not
F:\ or G:\, when three drives are inserted in the computer.

So you expect the drives under F: or G: but there are
no F: and G:?

The USBDLM didn't do its job. As the others asked: What
shows the Disk Management about the drives?

Here is a pre version of USBDLM 2.0:
http://www.uwe-sieber.de/files/usbdlm199.zip

It writes debug information that should show me what is
going on when you attach the drives. To grab the debug
output you can use Sysinternals DebugView:
http://www.sysinternals.com/Utilities/DebugView.html


Greetings from Germany

Uwe