I can’t use my thumb drive

Question

I can’t use my thumb drive on my computer. I have tried going to Properties and change owner to everyone and granting full access. It still says I don’t have permission to make changes . It’s been awhile since I have used a thumb drive. But since when has it gotten so complicated to use a basic thumb drive. I am stumped.

Answer 1

Hello, thank you for reaching out to Microsoft Q&A.

If the USB drive is empty, you can format the disk.

Open the command prompt as Administrator. Run these commands one by one and click Enter for each command.

diskpart
list disk
select disk X
clean
create partition primary
select partition 1
active
format fs=ntfs quick
assign
exit

Replace X with the thumb drive disk letter.

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If there are any important files on the disk and you don't want to format it, just share a screenshot of the error message you get when you try to access the thumb drive.

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Answer 2

On many Windows systems, access to USB/removable drives can be blocked or restricted by policy or registry settings, regardless of file/folder permissions on the drive itself. Changing the drive’s owner or NTFS permissions does not override those system-wide controls.

Check the following common causes:

1. Verify if removable storage is being denied by policy
   1. Press Windows + R, type MMC.exe, and press Enter.
   2. In the console, go to File > Add/Remove Snap-in (Ctrl+M).
   3. Add Group Policy Object Editor, click Browse, go to the Users tab, and select Non-Administrators (or the relevant user group), then Finish > OK.
   4. In the left pane, expand:
      • Local Computer > Non-Administrators Policy > User Configuration > Administrative Templates > System > Removable Storage Access.
   5. Double-click All Removable Storage Classes: Deny All Access.
   6. If it is set to Enabled, this blocks read/write access to USB drives. Set it to Not Configured or Disabled, then click Apply > OK.
   If this policy is enabled, it will cause “no permission” or similar errors on thumb drives even if NTFS permissions look correct.
2. Check if the USB storage driver is disabled (if the drive never works on this PC) If USB storage devices are globally disabled, the system may prevent use of thumb drives:
   • Open Registry Editor (regedit) and navigate to: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\UsbStor
   • Check the Start value. If it is set to 4, USB storage is disabled. Changing this value requires care because incorrect registry edits can cause system issues. The documented behavior is that setting Start to 4 prevents USB storage devices from working when connected.
3. Confirm the drive is not being blocked as removable media If the system is hardened against removable media, it may be using the removable storage access controls described above to prevent read/write access to any device detected as “Removable media” or “External hard disk media.” In that case, either:
   • Relax the removable storage access policy as in step 1, or
   • Use encryption/BitLocker and appropriate policies if the goal is to secure but still use the drive.

If the thumb drive works normally on another computer, but not on this one, focus on the removable storage access policy and USB storage driver settings as the likely cause, rather than NTFS permissions on the drive.

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References:

• NTFS disk access permissions for removable or external media could be bypassed
• How can I prevent users from connecting to a USB storage device?