New Drive Appeared

Hi

I have noticed a new drive has appeard on my Asire Aspire ES1 531 Laptop, it is described as ESP(Z, on clicking it I am told i do not have permission to access this folder, which concerns me.  Why and how has it appeared, should it be there?  If not how do I remove it.

I am no computer wizard, so any answers/advice in very simple terms would be appreciated.

Thanks