This article deals with the causes of the message "Could not initialize the browser's security component. The most likely cause is problems with files in your browser's profile directory. Please check that this directory has no read/write restrictions and your hard disk is not full or close to full. It is recommended that you exit the browser and fix the problem. If you continue to use this browser session, you might see incorrect browser behavior when accessing security features.".
For information on other messages received when attempting to load web sites, see Error loading web sites.
If the issue began appearing after upgrading Firefox on a Windows 98 or Windows ME system, you may be missing some Windows files required by Firefox.
The easiest way to install these files is to Install IE 6.0 SP1, which provides the correct files. To download and install it, visit Microsoft's site.
Check your hard drive's free space.
If it reports less than 1MB free space available, you'll need to make more room.
Check the file permissions in your profile folder. The file named cert8.db must not be read-only.
Restart Firefox and the problem may be fixed.
The file cert8.db in your profile folder may have become corrupted. Delete this file while Firefox is closed.
Your settings may have become corrupted due to changes in your system or a lack of hard drive space at one point. Create a new profile with the Profile Manager. If the problem goes away, you can then move your settings to the new profile. If the problem remains, you can go back to your original profile.
Based on information from Could not initialize the browser security component (mozillaZine KB)
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