I used to get this message all the time on my previous computer, but it would be several of them. I was running a Windows 8 machine, 12 GB of RAM, and several card readers slots. The drive letters displayed would be from my card reader. I would get these messages when I tried to open any PDF. If you continue clicking on "Continue" the PDF would still open. I personally thought it was annoying, but since I did not have to open too many PDF documents I just suffered through it. I recently moved to a new machine and the message stopped. BUT at the same time I moved to a new machine my boss moved to a new machine. Now he is getting the message. Unlike me, he is only getting one message and his machine doesn't have a card reader. He is running a Surface Pro (Windows 8, 4 GB of RAM). The other user with a Surface Pro is not reporting any issues. Any idea on how to fix the issue? We have tried uninstalling Adobe Reader and re-installing it, but no luck on fixing it.