Did you recently refresh Firefox? That will cause the "Old Firefox Data" folder to appear on the desktop. The "Old firefox Data" basically is old Firefox data, as the name implies. You don't need it, but you can use it as a back up if you wish, although it is very unlikely that you will need or want it. Check out this thread for more details. This folder is not related to updating firefox.

Have a great day!!

Jon

I don't remember if that question has much to do on what it can be used for, but basically it can be used as a back up. The thread I posted does give directions on how to view your current profile data.

When you reset Firefox then a new profile is created and some personal data (bookmarks, history, cookies, passwords, form data) is automatically imported and the current profile folder will be moved to the desktop to an "Old Firefox Data" folder. Installed extensions and other customizations (toolbars, prefs) that you have made are lost and need to be redone.

It is possible to recover data from the old profile, but be cautious not to copy corrupted files to avoid carrying over problems.

See:

• https://support.mozilla.org/kb/Recovering+important+data+from+an+old+profile
• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

See also:

• https://www.mozilla.org/en-US/firefox/37.0.2/releasenotes/

Thank you much. This explains why I thought the recent update was such a big problem. The update was probably waiting to be loaded, but when I went to Flickr I received a message something like, "You are using an unrecognized browser......please reload your browser." So I pushed reset by mistake and that's when the latest update appeared. Oh, well. I'll see if I can just reload add-ons I was using (although I've reloaded adblock already) and permissions I may have allowed or revoked. Everything else is settling down already.

Thanks for your help, BAB