Thanks, but the batch file deleted a bunch of stuff in the SOURCE directory! mn

Clearly that depends on the file sizes. If it's media files, the check takes far longer than the copying. And with the check, it's not at all inefficient to update 40G of files, even many times a day. The deletion process - which normally involves no more than a dozen files or so -...

Thanks - as I understand it, SYNC /W will copy newer files from dir2 to dir1, and therefore from the destination drive to the source drive. Though that's usually no problem, I want an absolutely 1-way process from drive 1 to drive 2. On rare occasion I'll have a newer version of a file on...

I have tried for some time, without much success, to do a btm file which will delete all files on Drive 2 that are not on Drive 1. (I'm using 4NT.) I don't need to check for anything but file-names. Any help with this much appreciated.