Sometimes malicious files from e.g. malware is stuck in the application folder even if you uninstall - this is because Firefox only removes the files it installed itself. If there are other files that are interfering, they will be kept in the application folder even if you uninstall.

Could you try to completely uninstall by also removing the application folder? See the specific instructions here: https://support.mozilla.com/en-US/kb/Basic%20Troubleshooting#w_7-reinstall-firefox

Thanks, I tried that, and no luck. I have tried uninstalling, deleting the Mozilla Firefox folder, and also deleteing my profile, then reinstalling. Are there register keys that need to be deleted? Maybe this information from the error will help: Add-ons: AvailableVirtualMemory: 2052681728 BuildID: 20110922153450 CrashTime: 1317225922 EMCheckCompatibility: true InstallTime: 1317225715 ProductName: Firefox ReleaseChannel: release SecondsSinceLastCrash: 58 StartupTime: 1317225922 SystemMemoryUsePercentage: 31 Theme: classic/1.0 Throttleable: 1 TotalVirtualMemory: 2147352576 URL: Vendor: Mozilla Version: 7.0

This report also contains technical information about the state of the application when it crashed.