Firefox crashes on start, even after complete reinstallation. No add-ons.

Question

Every time I open FF, it completely freezes within 5 seconds. I've uninstalled & reinstalled, I've removed FF & all traces of its data using Revo uninstaller, then reinstalled, and still get the same results. I've seen where malware could cause this kind of problem, so I've run full scans with Microsoft Security Essentials, Malwarebytes, Microsoft Security Scanner, and Kaspersky Security scanner. They all came back clean.
I'd love to submit a crash report, but apparently these crashes aren't generating them. The only thing in AppData\Roaming\Mozilla\Firefox\Crash Reports is an InstallTime file, dated today (the date of my most recent reinstall). I also can't add any troubleshooting information, as FF crashes before I can add anything.
Here's exactly what happens: I launch FF, whish responsive for the first couple seconds. After that, it freezes completely, and eventually "(Not Responding)" is added to the title bar. A little bit later, Windows pops up, asking if I'd like to check for a solution. That's it.
Win 7 Pro, FF 18.0.2.

Answer 1

Hello bob287, can you start Firefox in [https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode#os=win7&browser=fx18 Safe Mode] by holding down the shift key while starting Firefox ?
also, 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.
thank you