Firefox keeps crashing on startup, how can I fix it? I've already uninstalled it and reinstalled it, same problem.

Question

It doesn't even load the window. It just says that it crashed and gives me this:
Problem signature:
Problem Event Name: BEX
Application Name: firefox.exe
Application Version: 31.0.0.5310
Application Timestamp: 53c75e72
Fault Module Name: nsib.dll
Fault Module Version: 5.1.3.1
Fault Module Timestamp: 53f5c0ba
Exception Offset: 00135fe0
Exception Code: c0000005
Exception Data: 00000008
OS Version: 6.1.7601.2.1.0.768.3
Locale ID: 1033
Additional Information 1: 0a9e
Additional Information 2: 0a9e372d3b4ad19135b953a78882e789
Additional Information 3: 0a9e
Additional Information 4: 0a9e372d3b4ad19135b953a78882e789
Help

Answer 1

A "BEX" error often indicates there is a malware process trying to inject itself into Firefox in an inappropriate way, so Windows shuts it down to protect you.
When I search for information on nsib.dll, it's inconclusive. For example: [https://www.virustotal.com/en-gb/file/7739cad2495359a139ef31062f54d683ce549bc4d7cca13f8d1cdaca86b3474d/analysis/ VirusTotal analysis].
Assuming it is a bad add-on, I suggest starting here:
Open the Windows '''Control Panel''', Uninstall a Program. After the list loads, click the "Installed on" column heading to group the infections, I mean, additions, by date. This can help in smoking out undisclosed bundle items that snuck in with some software you agreed to install. Take out as much trash as possible here.
You can "mop up" remaining issues with the scanning/cleaning tools suggested in this support article: [[Troubleshoot Firefox issues caused by malware]].
Finally, start Firefox in its Safe Mode by holding down the Shift key when double-clicking the Firefox shortcut/icon. In the small dialog that should appear, choose "Start in Safe Mode"
Then open the '''Add-ons page''' using either:
* Ctrl+Shift+a
* "3-bar" menu button (or Tools menu) > Add-ons
In the left column, click Extensions. Then, if in doubt, disable (or Remove, if possible) unrecognized and unwanted extensions.
Often a link will appear above at least one disabled extension to restart Firefox. You can complete your work on the tab and click one of the links as the last step.
Does that clear it up?