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Firefox will no longer start after downloading the last update

Ronald Krumpen
Ronald Krumpen
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Yesterday (2/7/14) I downloaded the latest Firefox update. While the update was being installed I got a Parse error message. When I tried to restart Firefox nothing happened. I tried reinstalling Firefox (both with and without uninstalling the old version) and Firefox would start at the end of the installation process but after I closed Firefox it would not restart. I tried starting it in the safe mode but that didn't work. When I use the Task Manager Processes tab I see Firefox open for about a second and then it disappears. I was finally able to get it to open by using Windows Explorer to set the compatibility mode of the Firefox.exe file to "Windows 2000" but I don't think that is a good solution. Note that I am running the Windows XP Professional operating system.

Yesterday (2/7/14) I downloaded the latest Firefox update. While the update was being installed I got a Parse error message. When I tried to restart Firefox nothing happened. I tried reinstalling Firefox (both with and without uninstalling the old version) and Firefox would start at the end of the installation process but after I closed Firefox it would not restart. I tried starting it in the safe mode but that didn't work. When I use the Task Manager Processes tab I see Firefox open for about a second and then it disappears. I was finally able to get it to open by using Windows Explorer to set the compatibility mode of the Firefox.exe file to "Windows 2000" but I don't think that is a good solution. Note that I am running the Windows XP Professional operating system.

All Replies (4)

cor-el
cor-el
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  • Top 10 Contributor
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Did you try to delete the Firefox program folder before reinstalling?

You can find the full version of the current Firefox 27.0 release in all languages and for all Operating Systems here:

Ronald Krumpen
Ronald Krumpen Question owner
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Yes, I uninstalled Firefox, deleted the program folder, and then reinstalled Firefox. Firefox still would not start until I set the compatibility to Windows 2000.

cor-el
cor-el
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  • Top 10 Contributor
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Try to boot the computer in Windows Safe Mode with network support (press F8 on the boot screen) as a test to see if that helps.

Ronald Krumpen
Ronald Krumpen Question owner
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I tried that and it didn't work.