Adobe Flash is notorious for not always removing old Flash Plugin DLL files as part of a Flash program update. Sometimes the user needs to uninstall Flash completely and get a clean start.

First, grab the Adobe uninstaller from here: http://helpx.adobe.com/flash-player/kb/uninstall-flash-player-windows.html

Then download the latest Flash Plugin version from here: Select the Windows > Plugin-based browsers - the EXE version. https://www.adobe.com/products/flashplayer/distribution3.html

Run the Flash uninstaller program, then reboot your PC. Then install the Plugin version of Flash. So you'll have a clean installation of Flash for Firefox.

If, for whatever reason, the above doesn't work;

Type about:plugins<enter> in the address bar. Now search for the plugin.

Example; Adobe Acrobat File: nppdf32.dll,nppdf32.dll Path: C:\Program Files (x86)\Adobe\Reader 11.0\Reader\browser\nppdf32.dll,C:\Program Files (x86)\Adobe\Reader 11.0\Reader\AIR\nppdf32.dll Version: 11.0.9.29 State: Enabled Adobe PDF Plug-In For Firefox and Netscape 11.0.9

This will show you the path to that program. Copy the Path Only. Also note the name of the file, and remember it. Now Close Firefox. Open your file browser and paste the path in the address bar. Find the file, and delete it. Now you can restart Firefox. Warning ! Remember to delete the right program.

To be safe, remove all of them. Then install the current.

eam2 said

I have been unable to watch videos on certain websites - I keep getting the message that I need to update my Flash. I have updated, to Flash 20, but the websites don't appear to recognise it and still think that I only have Flash 18. I have checked in the Add-ons Manager; Flash 18 is disabled, and Flash 20 says "ask to to activate". I have tried to remove Flash 18, but all I have managed to do is remove Flash 20. How do I get rid of it altogether?

earn2, did you try it. did it work? I ran a search and found no Flash DLL files older than one month. so I am skeptical