Please update Firefox to the latest version: Update Firefox to the latest release

If this continues to happen, please check to make sure that there is not an antivirus that is blocking Firefox from running.

Try to disable hardware acceleration.

• Tools > Options > Advanced > General > Browsing: "Use hardware acceleration when available"

If disabling hardware acceleration works then check if there is an update available for your graphics display driver.

thank you guigs2 for your answer: but the problem still happen :( I can't solve it i reinstalled my windows and did all steps

Something on your computer is causing this issue.

Sometimes a problem with Firefox may be a result of malware installed on your computer, that you may not be aware of.

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

• Microsoft Safety Scanner
• MalwareBytes' Anti-Malware
• Anti-Rootkit Utility - TDSSKiller
• AdwCleaner (for more info, see this alternate AdwCleaner download page)
• Hitman Pro
• ESET Online Scanner

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.

Did this fix your problems? Please report back to us!

the same problem :( :( :(

Start your Computer in safe mode. Then start Firefox. Try Safe web sites.

Starting The Computer In Safe Mode;
Free Online Encyclopedia

then ?????

I think the problem was because of Anti-porn I uninstalled it and it solved, Thank you very much for your answers :)

That was very good work. Well Done. Please flag your last post as Solved Problem so other will know.