Tobylerone

Hi there, I'm new to the forum so I apologize in advance if this question has been asked a million times before, I did use the search button but didn't find anything that answered my questions as such. I have a small network in my workplace and will soon be looking to recruit new staff, the problem is, I don't want the new employee's to have full access to the shared folders. I have tried and tested numerous software in the last 48 hours but I haven't quite found what I'm looking for! Is their any free software out there that simply allows you to right click a shared folder and set a password? I hope that someone can point me in the right direction. Thanks