Any copy program has a problem when the file about to be copied has the same name as a file already in the output folder. Should the file in the output folder be replaced with the one being copied, or should the copy not take place?
The Key gives you four options to tell it what you want it to do in such cases. Select the desired option by checking the box next to it.
If you check the ``Always" box, The Key will copy every file in your input folder and always replace existing files whenever name conflicts occur.
If you check the ``Only if different" box, The Key compares every input file with the corresponding one in the output folder, and only copies those that differ. The effect is the same as if you said ``Always", but this is much faster if only a few files actually differ. For example, you might want to use this option if a few of the files on your hard disk have been damaged and you don't know which ones.
If you check the ``Only if older" box (the default), The Key compares the dates of the input and output files. If the output file is older than the input, it copies, replacing the output file by the input; otherwise it leaves the output file alone. The result is that whichever version is newer ends up in the output folder. This is useful, for example, when you want to merge two folders with different versions of the same files.
If you check the ``Never" box, The Key will never write over an existing file. This of course is the safest in the sense that files are never destroyed, but it may leave you with old versions of files.