Copying files to new server

Hello all,
I just build a new server and it is in the domain. I need to copy about 100GB worth of files/folders from the old server to the new server before retiring the old one. I doing a copy and paste over the network. I noticed that by doing it that way, I am getting the “Read Only” option checked on the copied folders. I am sure that there is a better way to move the data from old server to the new one without the read only issue. How would I go about doing it? Your help is greatly appreciated.