Device Control Question

  • 25 October 2019
  • 4 replies

Using KSC and KES

Using Device Control, I am trying to control access to USB Ports. My Goal is to Deny USB Removable Drives, and Cell Phone storage. When I turn on Removable Drives Access to limit Except for a Support group, It works But…. When we access a USB External Hard Disk it is denied access.

If I do Not have “Portable devices (MTP) Blocked, I can use as desired except that cell phone storage can be accessed. Why would a External USB Hard disk be Blocked using the MTP item?

I attempted to allow a trusted device and could not get that to work properly.

4 replies

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Is the USB HDD detected by OS as MTP? 

Thank you!

How would I know if the USB HDD is detected by the OS as MTP?

When I plug in the USB HDD and Go to Control Panel, Devices and Printers, I see the Drive and the properties on the General Tab say “Categories: Storage Device”

The Hardware Tab Shows the Name of the Drive as “Portable Devices”, and the WD 50000AAV External USB Device as a Type of “Disk drives”.

Does that answer what you were seeking?



Silence is not a value to me.

I opened a Ticket with support and they also cannot resolve it.


I can control the USB Memory sticks without any issues.

When I plug in an iPhone or External Hard disk they are both identified as “Portable devices (MTP)”

In the “Portable devices (MTP)” access I removed the check for Read and Write for the Everyone account. the Added System (NT Authority\SYSTEM) added a check for Default Schedule and Read, Write. Then added my UserID with adding a check for Default Schedule and Read, Write.

I get the message that it has been Blocked.

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