I just tried to do something similiar, backup my project on V7 from my project files to a second internal drive I have and I received the error
Input file read failure-This srror occurs when a file read operation is performed on a zip file that is locked or restricted by another process
I have backed up my project several times before with out any problem. The only thing that I have done since the last backup, was add several photos to some of my names, and run the Utilities program and Second site program that I received on the October cruise.
Later today I will try other options that have been suggested already.
Alan