Just encountered an error that one my user has on his workstation, any CD/DVD that he inserted into the DVD-ROM drive will pop-up an error message indicating that access to the CD/DVD media is denied. The same thing goes for his USB drives, insert it into any of the USB port, the same error message.
After reading through the Windows event log, I managed to figure out that the stupid Acer eManagement software is denying access to any removable drives. Removed those stupid Acer eManagement and eProtection programs, restart the workstation and finally the user is able to access the CDs/DVDs and read his data from his USB drive.
So if you have the same problem with your Acer workstation, remove those stupid Acer programs that has been installed by default at the factory.
Chiawy's Blog 