Every time I log onto Firefox I get the following message: "Could not initialize the application's security component. The most likely cause is problems with files in your application'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 application and fix the problem. If you continue to use this session, you might see incorrect application behaviour when accessing security features." I would like to fix whatever is causing this error message to appear, but I haven't found my, "application's profile directory" so that I can check for "read/write restrictions". My hard drive is 640GB with 554GB free space remaining. I am running Windows 7 - 64 and am using Avast Internet Security 2013.