Free Lab Managment Software

Hello,

Do you know of any friendly software that would allow me to upload or edit folders on student computers from the teacher computer? I do have an external harddrive that is connected to our server but I still have to save or make changes on all 50 computers. I am teaching my students K-3 how to make power points etc. When new students move in I add their pics to all computers for projects. All updating takes forever (50 times). Thank you so much for your help!