External storage device won't open

Hello,



Whenever I insert a disk into my computer it loads and shows disk ready for use but won't open. I have tried several methods I saw online but to no avail. When I tried one of the methods I saw a dialogue box appeared bearing this information that my external disk is restricted from opening in effect to the system that I should contact the system administrator in order to remove it.
Please somebody should give me guidelines on how to remove the restrictions.