Took me a while to figure out the most effective way to get all of your photos / videos onto your windows box.
The following is a link with details and some of my notes.
If you go to this link you:
http://osxdaily.com/2016/05/26/download-photos-from-icloud/
Search in the page for this:
follow the instructions.
Some notes.....
You will have to install the iCloud for windows desktop app.
Opening the iCloud app you can specify windows directory locations.
On window search bar: iCloud Photos and click
Download photos and videos on tool bar.
All
.... will put in directory you specified in the iCloud app.
I had over 1600 pictures so it took a while to download all of them.