I've had multiple problems with Photostream, as I know others have as well. In the past when it stopped working on my PC, I could either log out and log back into iCloud Control Panel, or re-install it. Now neither works. Photostream still work fine transferring photos from my phone to iPad, but will not work with my PC. When I open the iCloud control panel, none of the boxes are checked. When I check the Photostream box, the options button highlights but won't open any options. Additionally, when I close the panel with Photostream checked, then re-open, the check has disappeared. Anybody else having this problem?