As part of our back up system I want to copy each of our 4 PCs hard drives over the network to a USB external HDD. However none of the PCs will let me copy the Program Files folder. I have also found that I cannot access this folder from another pc on the network. This means that a program that is designed to be shared across the network or keeps its data in a subfolder of this folder cannot be used or accessed by another pc. I have tried to share these folders but sharing is grayed out. All four pcs are set up as administraters. Any suggestions would be most gratefully received