File transfer over intranet network

I'm looking into the idea of keeping computer system images at each of our locations so that in the event of a hard disk crash we can load a fresh image over the local network. I can't do this from a central server since some of our satellite stores are on slower 80KB/sec connections and it would absolutely decimate the store's Internet connection.

The largest image I have is about 3.4GB in size. What I want to do is have my program run during the off hours and copy these large images. However, due to their size I would need to be able to stop a transfer and pick up from where it left off the following day.

Is there an *easy* way to do this using any built in VB6 controls or would I have to write my own client/server app that can resume a broken download? I'm open to ideas and suggestions.

If it has to be in VB6 you'd have to write your own, but you could make it easier by using an FTP server capable of resuming as your server.