Hi there.

By junk files do you mean cache and cookies? Firefox offers some basic functionality like clearing your cache on exit, but for more comprehensive and customizable clearing I would suggest CCleaner: http://www.piriform.com/ccleaner. CCleaner is free, established and widely trusted - just make sure you say No to the "free software" offer in the installer, as those are mostly junk. ;) The program will not nag at you or pop up ads when you use it.

As for configuration, I would just leave Firefox at default settings as those work for the majority and are optimised with each update. If you feel your configuration has become decrepit, you can Refresh Firefox to restore your profile to its former glory: https://support.mozilla.org/en-US/kb/refresh-firefox-reset-add-ons-and-settings.

Refreshing essentially ports your old data into a new profile. Do note that it requires add-ons to be installed separately, but a fresh install might not be a bad idea in the first place - also a chance to see if you need or want them all.

If you would like some help with particular Firefox settings, feel free to ask.

If you have submitted crash reports then please post the IDs of one or more recent crash reports that start with "bp-".

• bp-xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx

You can find the report ID of recent crash reports on the "Help > Troubleshooting Information" page (about:support).

• click the "All Crash Reports" button on this page to open the about:crashes page and see all crash reports.

Alternatively you can open about:crashes via the location/address bar.

See also:

• http://kb.mozillazine.org/Mozilla_Crash_Reporter
• https://support.mozilla.org/kb/Mozilla+Crash+Reporter