This means that either the file is currently in use by another program, or that the folder, for the destination of the file, has write protection (i.e. read only) applied to it.
To fix for the file in use:
Close the file in use, and
Then try to save the FAID Quantum file.
To fix for the Write Protected folder:
Navigate (ie using windows explorer) to the folder where saving to
Right click – select “Properties”
Unselect the Read Only attribute.
To fix for the Write Protected folder for Windows Vista:
From the Program Start Menu find the FAID Quantum program icon
Right click – select “Properties”
Under the “Compatibility” tab tick “Run this program as an administrator”