Window is unable to complete format

I have a 16gb Sandisk memory card and for some odd reason its not working now. When I try to delete everything it saying "Cannot delete make sure you mobile device has sufficient memory, that the file is not set as read-only, and that you have permission to copy this file" Can someone tell me how I can make my memory card work again even if I have to take everything off of it. When I try to access the memory card on my mobile phone it saying that the access is denied. I dont want to get another one because I dont have the money now. I am not sure if the card is locked or not don't know to much about it. Any suggestion.
Is there a program that will help me with this. I can erase everything if i have to it dont matter. I have an 16 gb sandisk

Does the card have a switch that allows it to set to read-only? Its often tiny and some people don't know what its for.