I recently realized that defragmenting my C-drive, AFTER making a complete new image, can significantly (& unnecessarily) increase the size of subsequent differential and incremental images. I am disappointed with myself that it took me a ridiculously long time to figure out such an obvious fact. I now plan to schedule necessary defragmenting of C-drive to be done just BEFORE I make a complete new image. That should save me a good bit of storage space. I make this confession on the off-chance that someone might profit from my goof-up.