I have Windows Vista. On March 13 or 14, Firefox froze after a Windows automatic update. A popup window said Firefox was not compatible with Windows. Since I have auto update for Firefox, I am pretty sure that I have the latest version. I was unable to close this error message. When I restarted the computer, the problem recurred. I used IE to download Firefox anew and then was able to close the error message and all seems well now. Is this a problem caused by Microsoft or just a coincidence?