firefox.exe produces close to 100% CPU usage upon closing.




9 years ago
9 years ago


(Reporter: louietyj, Unassigned)


Firefox Tracking Flags

(Not tracked)




9 years ago
User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv: Gecko/20091221 Firefox/3.5.7
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv: Gecko/20091221 Firefox/3.5.7

After clicking on the X button to close Firefox, the firefox.exe process in Task Manager uses close to 100% of the CPU. Attempts to open Firefox again through the start menu or desktop will give a notice along the lines of "there is already a firefox process running, please close that process or restart Windows". Firefox will not load until firefox.exe is terminated from Task Manager or Windows is restarted.

Reproducible: Sometimes

Steps to Reproduce:
1. Open Firefox.
2. Open a few websites in tabs (try:,,
3. Close Firefox.
Actual Results:  
The computer responds extremely slowly and Task Manager shows firefox.exe using up close to 100% CPU.

Expected Results:  
firefox.exe should have been properly terminated?
can you reproduce the issue within "safe-mode" ( testing a set of certain sites what you know of producing your mentioned behaviour? maybe also disable temp. your security apps.

Comment 2

9 years ago
I've tried, but then again I haven't been able to reproduce this problem, safe mode or not, intentionally until it happens, and I realize I forgot to write down the list of sites I went to. Nobody else has the same problem?
I have not seen it with Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.3a1pre) Gecko/20091228 Minefield/3.7a1pre (.NET CLR 3.5.30729) ID:20091228043113.

Comment 4

9 years ago
I'm looking at something like this:

I haven't been able to find out exactly what causes this though...

Comment 5

9 years ago
Unless you can reliably reproduce this we don't have enough information to investigate the cause.
Last Resolved: 9 years ago
Resolution: --- → INCOMPLETE

Comment 6

9 years ago
I'm pretty sure it's caused by certain extensions, I heard one of them is Ghostery.

Another one is the Winamp toolbar(I got it from installing Winamp itself, no Mozilla Add-on)

I can confirm the second, after I removed it, everything worked perfectly fine. Adn I tried several times so I'm really sure of it.
J.Schmiddunser, please report problems with extension to the extension developers. Ghostery is bug 538160
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