Fixing “Access Denied” with USB devices in Windows 7

I recently had the pleasure of experiencing the dreaded “access denied” error when trying to share a USB drive with a Windows 7 machine.  Here’s how to fix it.

I have a USB disk (Fantom 1.5 TB “green” drive) that I share with multiple operating systems: OS X, Linux, and multiple versions of Windows.  I had not tried to access it using Windows 7 before, and when I did, I thought things were okay initially: Windows gave the typical “installing drivers … ready for use” messages when I connected the drive.  But from there things got a bit strange: Windows gave the drive’s NTFS partition a drive letter and knew how much space on it was used and free, but when I tried to access the drive’s data via an application or Windows Explorer, I got the error: “[My disk label] is not accessible.  Access denied.”  I started poking around with ownership and permissions, but this resulted in odd “you are not the owner” errors, or even worse: messages that claimed that Windows could not determine the owner of the device.

I did a lot of searching for an answer, and found suggestions to make additional changes to permissions and ownership, but none of these worked.  Finally, there was something that did work: apparently, Windows 7 simply can’t make sense of the partition table on drives that were partitioned by earlier Windows version.  I didn’t want to hose my entire drive, or to mess up the disk’s partition table so that my other machines wouldn’t be able to access its existing data.

The solution was to download a free partitioning product called Partition Wizard Home Edition, and to have this application simply scan — not edit anything, but just scan — the existing partition table on the drive.  For whatever reason, after this scanning, which took less than a minute on my drive, Windows 7 was instantly able to view the contents of the disk and allowed me to access its contents.


22 thoughts on “Fixing “Access Denied” with USB devices in Windows 7

  1. Pingback: Fixing “Access Denied” with USB devices in Windows 7 « A DeStefano … | Windows 7 Keygen

    • Thanks for mentioning that, Pranav. I’ve just tried a recent version and can confirm what you’re seeing; I wish I’d taken a screen shot of a previous version, which did have this capability, but it does now seem to be missing. I’ll be looking for a replacement, or perhaps it’s worthwhile to ask the developers what’s happened, and why ….

      • this command does not work as it fails with the following error:

        ERROR: Invalid argument/opt – ‘e:’

        I tried variations of this but couldn’t get it to work. I’m still looking for a solution to this problem.

      • John, I tried your suggestion and received the following error:

        ERROR: Access is denied.

        I even tried it within the command prompt with elevated credentials and received the same error.

        Any other suggestions? Thx!

      • takeown /R /F e:\* (where e is the drive letter) work great for me

        It scanned through all files on the drive and found 1 file that apparently did not have the correct permissions. I just confirmed ownership and now the drive is accessible. THANKS!!

  2. If you can’t access just only one FOLDER on your USB try to take ownership.
    Properties, security, advanced, advanced, advanced, ownership.
    Don’t forger to choose user you are logged in.

    This will help (:

  3. I tried all the things…i think it is blocked by the group policies or from the antivirus…need a help..still no luck for me…

  4. Thanks a lot John..

    I tried all the option with the (USB Drive -> Properties –> Security Tab), but failed in opening drive.
    But this Partition Wizard only helped..

    Thanks again…

    Emsyne Tech.

  5. Hi everyone. It perfectly worked for me. With the new version I made a surface test. And then all worked perfectly ! Thanks !

  6. Jesus at those answers to a simple problem….SImply change the permissions and add “Everyone”, problem sorted.

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