Yesterday, July 25, my laptop did an automatic update. I don't know what was updated since I left the room, but suspect it was Windows, updating to 8.1. Since then, Mozilla Firefox won't open when I double-click the button. (Also, my machine lost its automatic re-direct to DuckDuckGo. And the automatic opening of my gmail account also disappeared.) I tried to find out why Firefox wouldn't open and some little program told me it was incompatible with Windows 8.1 Today I downloaded Mozilla Firefox for Windows 8 again. The program sent me a message saying Firefox was already installed. Things are getting messy. I should check what programs are operating on my machine. Has anyone had this problem - an update to Windows rendering Firefox unusable? If so, how did you solve it? Thank you.