I'm sure I did something to cause this, but, not sure what. On my desktop I have my "MacintoshHD" icon as well as another icon exactly like it, except there is a small arrow pointing to it at the lower left side. What did I do? And, what do I need to do to get rid of this? I searched for this particular situation in the other threads but found nothing. There is a jpeg of the two icons attached. Thanks for your help.

