diskpart only showing half of total space for USB drive

C

Citizen Snips

Limp Gawd
Joined
Jan 6, 2009
Messages
171
I have a very old (2006) USB flash drive that was last formatted in Windows Vista. I plugged it into a Windows 10 machine and found that only half of the drive's space was visible. After some searching, I found this page that explains how to delete existing partitions, create a new one using all available drive space, then reformat:

http://geekswithblogs.net/ilich/arc...g-unallocated-space-of-a-usb-flash-drive.aspx

I followed those instructions but even diskpart is only showing half of the drive's total space when I run "list disk" after deleting all existing partitions. How do I recover the rest of the space if even diskpart can't see it?

Here is another piece of information:

When I plug the USB drive in and go to Device Manager, I see a new entry under "Universal Serial Bus controllers" called "Unknown USB Device (Device Descriptor Request Failed)".

I realize USB flash drives are now cheap, and I could just buy a replacement, but this drive was working fine before I plugged it into the Windows 10 machine and does everything I need it to, so I'd like to just keep it if possible. It seems odd that Windows 10 would have some backwards compatibility issue that would prevent early generation USB flash drives from working.
 
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you can format the disk in diskpart also.

Select disk #
clean
create partition primary
format fs=ntfs quick (for quick format to ntfs, you can do fat32 or whatever here also)
 
diskpart

select disk (whatever)

clean.

the go in to disk management and manage it.
 
lilfiend said:
you can format the disk in diskpart also.

Select disk #
clean
create partition primary
format fs=ntfs quick (for quick format to ntfs, you can do fat32 or whatever here also)
Click to expand...

Master_shake_ said:
diskpart

select disk (whatever)

clean.

the go in to disk management and manage it.
Click to expand...

Yes, I know you can format the drive from diskpart or the Disk Management program. The problem I am having is both of these utilities are only showing half of the drive's capacity even before a partition is created. The other half doesn't even show up as unpartitioned space; it just isn't there.

The yellow exclamation point in Device Manager under "Unknown USB Device (Device Descriptor Failed)" leads me to believe this is some type of driver issue. Do USB flash drives have built in drivers that are independent of the USB drivers used by Windows?
 
could be a dead or dying drive.

you haven't said it, but have you tried parted magic or something to see if it is windows's problem? and not the drive?
 
Did you get the drive from ebay? Sounds like you bought one of the scam drives that list way more capacity than it has, with a warning saying not all systems are compatible so they wont see the full size. Might even have some embedded malware on it too....
 
Citizen Snips said:
When I plug the USB drive in and go to Device Manager, I see a new entry under "Universal Serial Bus controllers" called "Unknown USB Device (Device Descriptor Request Failed)".
Click to expand...
Check in devmgmt again, and see what error code it reports when you open up the device dialog (while you're in there, try turning off power management for it)
Try a different port, I've also heard uninstalling then a reboot sometimes helps. You could also try checking the website of whoever made the motherboard for chipset/usb drivers (though it is Win10 so I kinda doubt that)?
 
There are SATA commands that can reduce the visible size of a drive. This is called host protected area. Not sure if this is in play.
 
Biznatch said:
Did you get the drive from ebay? Sounds like you bought one of the scam drives that list way more capacity than it has, with a warning saying not all systems are compatible so they wont see the full size. Might even have some embedded malware on it too....
Click to expand...

No, it was actually given out at a Micron recruiting event, although the drive was made by Pretec (presumably the flash memory was made by Micron)?
 
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ChoGGi said:
Check in devmgmt again, and see what error code it reports when you open up the device dialog (while you're in there, try turning off power management for it)
Try a different port, I've also heard uninstalling then a reboot sometimes helps. You could also try checking the website of whoever made the motherboard for chipset/usb drivers (though it is Win10 so I kinda doubt that)?
Click to expand...

I checked the "Unknown USB Device" entry in Device Manager (the one with the yellow exclamation point). Here is what it says under "Properties":

Windows has stopped this device because it has reported problems. (Code 43)

A request for the USB device descriptor failed.

I don't see an option to turn off power management for the "Unknown USB Device", but there is also a "USB Mass Storage Device" Listed. I disabled power management for that, but it didn't make a difference.

Another weird thing I noticed is that both the "Unknown USB Device" and "USB Mass Storage Device" have a Microsoft driver dated 6/21/2006. Is that driver built into the device? It seems odd Windows 10 would still be using any driver that old.
 
Master_shake_ said:
could be a dead or dying drive.

you haven't said it, but have you tried parted magic or something to see if it is windows's problem? and not the drive?
Click to expand...

I just tried EaseUS Partition Master and it is showing the same thing (only half space visible).

The drive worked fine as recently as last week when I last used it on a Vista-based system. I finally tore that system down and have been trying to use this drive on a Win10 laptop (USB 3.0 only) since then.

I should have a new desktop built by next week that has a couple USB 2.0 ports on the case. Maybe the drive will work correctly in one of the 2.0 ports. If not I guess I'll just buy a new flash drive as the amount of time I've spent troubleshooting this thing has almost surpassed the monetary cost of just buying a new, name brand, USB 3.0 flash drive. I just hate throwing away hardware for no reason other than software incompatibility.
 
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Sounds like they bought crappy drives to hand out at the conference. I would spend the 10$ and get a 16/32GB usb3 stick you know is good and call it a day. It's not worth the time or the RISK plugging in strange USB's into your system. You don't know where that stick has been stuck, or what diseases it might be carrying.

I say that in a joking fashion, but I'm completely serious. An unknown usb is about the easiest way possible to get bad stuff installed on your machine.
 
I believe Code 43 means an error with the device or the port.

All MS drivers are dated 2006 (Vista RTM date), it's so OEM drivers aren't overwritten by MS ones (version numbers do change).
 
Something else weird: If I unplug the USB drive, right click the "Unknown USB Device (Device Descriptor Request Failed)" and click "Uninstall", then click "Action" -> "Scan For New Hardware Changes", the "Unknown USB Device (Device Descriptor Request Failed)" entry comes back even though the drive is no longer plugged in. Does that make sense?

Also if I right click on Properties of the Unknown USB Device,

Device Type: Universal Serial Bus controllers
Manufacturer: (Standard USB Host Controller)
Location: Port_#0005.Hub_#0001

This computer only has 3 USB ports. Does that location make sense? Now I'm wondering if the USB ports are bad.
 
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