"List Disk" no longer recognizes thumb drives

Do you have a question? Post it now! No Registration Necessary.  Now with pictures!

Threaded View
I'm using Windows XP SP3. The instructions for a process I've  
used before start out with DISKPART from the command line to prep  
a USB flash drive (thumb drive). The first step within Diskpart  
is List Disk. The first time I used it, there was no problem and  
List Disk listed all available disks including the thumb drive.  
That was about a month ago.

Now I can't get any thumb drive to appear on the list.  
Unfortunately, in the interim period, I sold the thumb drive I  
used on that first occasion. Now I can't list any of the  
half-dozen thumb drives I have with me, including one which is  
the same model as the one I used before - a Sandisk Extreme USB  
3.0. List Disk just shows the SSD and two HDDs in my computer. My  
USB ports work just fine for any other job.

Can anyone suggest an explanation? I've bypassed the problem by  
using a different approach but I'd still like to know why List  
Disk no longer recognizes any thumb drive.  

Re: "List Disk" no longer recognizes thumb drives

Pimpom wrote:
Quoted text here. Click to load it

The Sandisk Extreme you just sold, must have been very new.
Sandisk sets the RMB bit on some of their new Flash drives,
to "fixed disk".

While you can find references to "a utility that flips the
RMB bit", it is largely a figment of the imagination. You
may succeed in trashing the USB Flash so that you cannot
use it. That is the most likely outcome. By comparison,
using a filter driver is safer. The trick then, is finding
a filter driver that runs on a modern OS.

You can tell how the RMB is set, just by the number of partitions
you can create (or mount). You're limited to a single partition,
if the device is "removable". Even if you format a USB Flash
in Linux, place four primary partitions on it, carry it to a
Windows machine, only the first partition will show up. The
other partitions will be ignored.

"Removable or what?"

I have nothing here currently, with the RMB declating
"fixed disk", so I have nothing to experiment with. All
my USB flash, only take one partition in Windows. And likely,
with no MBR to be seen. The only way they can have an MBR
is if they're prepped in Linux. The "fdisk" command can
lay in some partition table entries for you. But even
if you go to that extra trouble, Windows is only
going to mount the first partition. Until you can
fix the RMB issue.

    sudo fdisk /dev/sdg


Re: "List Disk" no longer recognizes thumb drives

Quoted text here. Click to load it

Thanks for the reply, Paul. I visited the link you gave but have  
not gone though it in detail yet. Here's some more info:

I said that the Sandisk Extreme USB 3.0 drive I have now is not  
recognized by List Disk whereas the one I sold was. One detail I  
omitted was that the one I have now is a 32GB unit while the  
previous one was 16GB. They look identical but came in different  
packagings (box and blister). The Extreme is one of the fastest  
thumb drives in the market and the 32GB piece is even faster than  
the 16GB unit (normal for flash drives), so I think there's  
little chance that it's a counterfeit.

After reading your input, I noticed that the 32GB unit I have now  
is seen by Windows as a removable drive. I already knew that the  
16GB was displayed as a ficed disk. So the RMB must be the key.

The process I referred to in my first post is the preparation of  
a thumb drive as a Windows 7 installation disk. There are  
essentially identical instructions on several different websites.  
None of them specifies a particular type or model of thumb drive.  
This implies that it should work with any thumb drive model.  
DiskPart is used to clean, partition, format etc. I used other  
utilities on the 32GB unit.  

Site Timeline