Rename (or delete) the mimeTypes.rdf file in the Firefox profile folder to reset all file actions.

• http://kb.mozillazine.org/mimeTypes.rdf
• http://kb.mozillazine.org/File_types_and_download_actions#Resetting_download_actions

You can use this button to go to the currently used Firefox profile folder:

• Help > Troubleshooting Information > Profile Directory: Show Folder (Linux: Open Directory; Mac: Show in Finder)

This stopped the tabs from opening one after another but now it opens a window asking if I want to open using Firefox Default and when I click okay it opens the same window again and again

Specifically, which website, which web page, and which hyperlink on the webpage does that happen with?

Typically, when this problem of an endless number of tabs or windows open with a single click, there is something set to open in Firefox that really isn't something which is intended to open and be viewed in Firefox.

It might be a setting in Firefox that isn't proper or it could be the website is mis-configured, or it could be caused by an external application that has messed up a setting for Firefox or in the Registry.

Not related to this problem, but you have three different versions of Flash in your Plugins listing in More System Details. Shockwave Flash 15.0 r0 Shockwave Flash 11.9 r900 Shockwave Flash 11.8 r800 You should remove the two older Plugins.

You should never select Firefox to open a file when you get the open with dialog. Firefox wouldn't ask if ti could handle this file.

What kind of links are you clicking when this happens?

Deleting the mimeTypes.rdf will reset all download actions to the default settings.

Type about:support in the address bar and press enter.

Under the page logo on the left side you will see Application Basics. Under this find Profile Folder. To it’s right press the button Show Folder. This will open your file browser to the current Firefox profile. Now Close Firefox.

Locate the file. Then rename or delete it. Restart Firefox.

The files are pdf