I have used Firefox on this Windows 10 desktop computer for at least 6 months with no problems. I have it set as my default browser. When I say it "does not start" I mean the hourglass is shown for a few seconds, then nothing. Task Manager does not show Firefox running. Since about 5 days ago it will not start when I click its icon on my taskbar or when I click on a link in an email. Both of these used to work. I have also typed Firefox into the Windows search box and clicked the icon then shown, but it does not start. I have googled the problem and tried a number of things, such as re-installing. When I do ''Windows-button & R'' to get the Run box, enter “firefox.exe -P” and click OK, the profile program does not start. When I run "Firefox Installer.exe" it goes through process and ends with Firefox open. That is how I was able to get in to get the Troubleshooting Information. However, I do not want to start it this way all the time, and it would not work on links in emails. I could not find how to add Tags. Thanks.