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Firefox fails to start and will not uninstall or be updated

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I am using Firefox version 18 on my HP PC. When I try to open it, I get the message: "The application failed to initialize properly (0xc0000005). Click OK to terminate the application." I have tried to update it from the Mozilla website and, however I try, if I get as far as it seemingly to have installed, when it starts exactly the same failure occurs. I have tried to uninstall it via the control panel and absolutely nothing happens. Internet Explorer also does not work. I have tried to restore to an earlier restore point. Whichever restore point I choose, system restore fails. This occurred just after I had been installing some card design and printing software, and my AVG system warned me that it had detected and prevented infection from several Adware viruses.

I am using Firefox version 18 on my HP PC. When I try to open it, I get the message: "The application failed to initialize properly (0xc0000005). Click OK to terminate the application." I have tried to update it from the Mozilla website and, however I try, if I get as far as it seemingly to have installed, when it starts exactly the same failure occurs. I have tried to uninstall it via the control panel and absolutely nothing happens. Internet Explorer also does not work. I have tried to restore to an earlier restore point. Whichever restore point I choose, system restore fails. This occurred just after I had been installing some card design and printing software, and my AVG system warned me that it had detected and prevented infection from several Adware viruses.

Chosen solution

Hello, try these free programs to scan for malware, which work with your existing antivirus software:

try all programs because each one detect different malware

Microsoft Security Essentials is a good permanent antivirus for Windows 7/Vista/XP if you don't already have one.

Further information can be found in the Troubleshoot Firefox issues caused by malware article.

also, what you have in Event Viewer ?


thank you

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All Replies (2)

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Chosen Solution

Hello, try these free programs to scan for malware, which work with your existing antivirus software:

try all programs because each one detect different malware

Microsoft Security Essentials is a good permanent antivirus for Windows 7/Vista/XP if you don't already have one.

Further information can be found in the Troubleshoot Firefox issues caused by malware article.

also, what you have in Event Viewer ?


thank you

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JJStillPatientlyTrying said

I am using Firefox version 18 on my HP PC. When I try to open it, I get the message: "The application failed to initialize properly (0xc0000005). Click OK to terminate the application." I have tried to update it from the Mozilla website and, however I try, if I get as far as it seemingly to have installed, when it starts exactly the same failure occurs. I have tried to uninstall it via the control panel and absolutely nothing happens. Internet Explorer also does not work. I have tried to restore to an earlier restore point. Whichever restore point I choose, system restore fails. This occurred just after I had been installing some card design and printing software, and my AVG system warned me that it had detected and prevented infection from several Adware viruses.

Thanks so much. I just followed the first 2 steps and problem solved. Step 1: Nothing detected Step 2: No malware was found, simply 117 unused items (in the Registry?)