Hi,
Have a look at robocopy with the /m switch. http://en.wikipedia.org/wiki/Robocopy
I had the same problem with a client running Vista and they were getting totally confused with auto backup features of their USB Drive.
When they run the script now it only takes out anything that has changed and also resets the archive bit, they have about 100GB of pictures to archive.

>Hi All,
>
>Just wondering what software/hardware combinations people were using to backup standalone PC's and notebooks?
>
>Have been looking at Western Digital passport drives and the bundled WDSYNC software for a client. The software works ok but it treats the Pc drive as the master drive when it syncs with the USB drive. This meeans that if you delete a file from the PC the next time you sync it is deleted from the USB drive - not what you would usually want!
>
>We have been approached by a number of unsophisticated clients of our business applications wanting to know what they should use for their notebooks and Pcs at home to backup documents & photos.
>
>Any thoughts and suggestions most gratefully received,
>
>TIA
>
>Andy