OK, I have re-read all of our posts.... I then checked the Apple site... The following article is the best I can come up with about the use of My Photo Stream. It applies to a Windows PC as well. I would follow the steps there slowly and carefully to see if they resolve your issue. Before you do that I would do a forced restart per my instructions below. A forced restart is simple, quick, and essentially "no risk" but has been known to resolve a lot of issues. I do not expect it to work here but you have nothing to lose by trying. Please do so. Then go to this article.
My Photo Stream FAQ - Apple Support
I would appreciate your feedback,
elcpu
Forced Restart: Hold down the Home and Wake/Sleep buttons at the same time for about 15-20 seconds until the Apple logo appears. Ignore the "Slide to power off" text if it comes up. You will not lose anything.