How to Fix Duplicate Shockwave Flash Player in Firefox

Removing Adobe DLM
1. Open the Firefox Internet browser.
2. Click 'Tools' in the upper left part of the window.
3. Click 'Add-ons' and a new window will pop up.
4. Click the 'Extensions' tab.
5. Find the extension titled 'Adobe DLM.'
6. Click 'Uninstall.'
7. Restart Firefox.
8. Install the Adobe Flash Player by downloading the software in the link located under 'Resources.'
9. Verify that there is only one Shockwave flash plugin by returning to the 'Plugins' list under 'Tools' > 'Add-ons.'
If There Are Still Duplicate Flash Players
10. Exit Firefox.
11. Find the Firefox plugin directory. This is normally located under 'C:\Program Files\Mozilla Firefox\plugins'.
12. Find the file named npswf32.dll and delete it.
If There is Still an Issue
13. Download the Adobe Uninstaller in the second link listed under 'Resources.'
14. Exit all applications.
15. Run the uninstaller and wait for the process to complete. Be sure to remove all Shockwave and flash applications.
16. Restart your computer.
17. Reinstall the Adobe Shockwave player using the file you downloaded in Section 1: Step 8.