JaneStream YOU ARE AWESOME!!! I have had this problem for over one year. The Program is HP Client Security. It will prompt for your WINDOWS PASSWORD, Select DEVICE PERMISSIONS, Select CHANGE and where it shows "Removable Storage", change it to ALLOW - FULL ACCESS.I thought I'd post a response even though this thread is getting old. I had this error message using a usb flash/thumb drive in my HP Elitebook. It turns out to be a HP security issue. I had to authenticate that I was the authorised person on this laptop to allow the drive to access the usb. An icon in the lower rh corner popped up prompting me to authenticate and it guided me through the authorisation process (it was quick). A message then came up saying I only had 15 minutes to access the drive data before it would shut down access again! Lol so I saved the document I needed on to my desktop to work on. Bloody annoying but that's security right? I hope this helps someone.
I was going to take it to Best Buy and probably pay them $100 because I was so frustrated with this.
THANK YOU SO MUCH!!!