Why is the size of my export of all photos/videos into Windows not the same as what iPhone/iTunes says my usage is?

It will take some time before I can verify but I think I know what happened.

Under the DCIM folder I had two subfolders. One is 796MB. When I try to view the contents of the other one, Explorer tries to index it so I can view the files but it craps out because it's so **** enormous.

When I used Explorer to drag-and-drop Windows 7 only copied this 796MB folder. My guess is the Import feature worked a little better but still didn't get everything.

I tinkered with trying to use DOS to copy the files over but got stuck because the iPhone isn't assigned a drive letter.

I ended up connecting it to our Windows 8.1 machine (which is also much more powerful) and am using Explorer to drag-and-drop the problematic folder. It will take a few hours to copy, which is a good sign. I will update and let you know if I can get Explorer to 44GB of videos and photos.

That is one of the methods I used. See my most recent reply, I think the sheer size of the folder broke Explorer.

Okay, so last night the simple drag-and-drop of the folder still failed. This morning I ended up transferring batches of files (sorted by date) in groups. That worked and I finally got 44.1GB of files off of my iPhone! I noticed at the bottom there were a lot of these 1kb "IMG" files that Windows detected which I suspect were the root of my problem. Perhaps they are iOS index files or something, I don't know. My Camera Roll includes I think 3 or 4 iPhone's worth of photos, so that is a lot of iOS versions these files have been through.

My next challenge is getting all 44.1GB onto a physical backup then figuring out how to cleanly delete all these photos. When I tried to delete one of the volumes using Explorer it wasn't able to, so we'll see what I can get done in iTunes.