Can't turn on Photo Stream in iCloud for PC

Hi,

My photo stream used to work fine. But after removing all the photos to separate folders in my computer, my new photos are no longer streaming to my PC. They appear in the photo stream on my other devices - iPhone5 and iPad Mini. It's just my PC that's missing the photos.

When I open the iCloud control panel, I cannot turn on the photos. That option is ghosted. I'm running on Windows 7 with iCloud 3.0. Any ideas on how I can fix this? All help is appreciated! Thanks!