Symptom
Your iPhone is set to back up your photos to iCloudiCloud on your Windows machine is configured to download your photosiCloud isn’t downloading your photo stream.Fix
1.Open the Task Manager by hitting Ctrl+Shift+Esc
2.Click the Processes tab
3.Click Name to sort the processes by name
4.Find the Apple Photostreams Uploader and Apple Photostreams Downloader processes. End both of them.
In Windows 7, these will be called ApplePhotostreamsUploader.exe and ApplePhotostreamsDownloader.exe5.Hold down your Windows key, and hit R to open a Run prompt
6.Type %appdata% and hit Enter
7.Open Apple Computer > MediaStream
8.Delete everything in the directory
9.Log out of your Windows account, and log back in (or just reboot, if you find that easier)
10.Once you’ve logged back into your Windows account, open the iCloud control panel again
11.If the Photos checkbox is empty, check it
12.Click Options, and make sure the photo options are configured how you want them
13.Click Apply
In a few moments, your photos should start downloading.
Notes
iCloud isn’t very smart about a great many things. Here are a few:
If you changed the location of your downloaded photos, it will redownload what it can, creating duplicates.In the iCloud 2.x days, your downloads and uploads were usually split into a Downloads and Uploads directory, and you could change the directories if you wanted. That’s not true anymore. Instead, iCloud 3.x creates a “My Photo Stream” directory, and sticks your downloads in there. Anything you’ve shared with other people, or that other people have shared with you goes into “Shared”. If you want to push a photo from your computer to iCloud, put it into Uploads