Hi jwsr71, what happens when you try to play YouTube videos. Is there a specific error message you could copy/paste or type into a reply?

What boxes are red for you on YouTube's HTML5 media support test page: https://www.youtube.com/html5

Media Foundation

Firefox on Windows 7 should be able to play YouTube videos without your having to do anything special. The exception is if you have one of the versions affected by the Microsoft antitrust settlement, you need to download some media components, or else Firefox can't handle H.264 video. This article has the details:

Fix video and audio problems on Firefox for Windows N editions

Add-on Check

If you installed any add-ons with names like YouTube Flash Player, you should remove those. YouTube no longer supports Flash, and those extensions can block YouTube from use alternate formats. You can view, disable, and often remove unwanted or unknown extensions on the Add-ons page. Either:

• Ctrl+Shift+a (Mac: Command+Shift+a)
• "3-bar" menu button (or Tools menu) > Add-ons
• type or paste about:addons in the address bar and press Enter/Return

In the left column of the Add-ons page, click Extensions.

Then cast a critical eye over the list on the right side. Any extensions Firefox installs for built-in features are hidden from this page, so everything listed here is your choice (and your responsibility) to manage. Anything suspicious or that you just do not remember installing or why? If in doubt, disable (or remove).

Any improvement?

General Suggestions

If a site is generally known to work in Firefox, these are general suggestions to try when it stops working normally on your Firefox:

Double-check content blockers: Firefox's Tracking Protection feature and extensions that counter ads and tracking may break websites that weren't built to operate normally without the blocked components.

Do you see a shield icon toward the left end of the address bar, near the lock icon? More info on managing the Tracking Protection feature in this article: What happened to Tracking Protection?.

Extensions such as Adblock Plus, Blur, Disconnect, Ghostery, NoScript, Privacy Badger, uBlock Origin or uMatrix should provide toolbar buttons to manage blocked content in a page. There may or may not be a number on the icon indicating the number of blocked items; you may need to click the button to see what's going on and test whether you need to make an exception for this site.

Cache and Cookies: When you have a problem with one particular site, a good "first thing to try" is clearing your Firefox cache and deleting your saved cookies for the site.

(1) Clear Firefox's Cache

See: How to clear the Firefox cache

If you have a large hard drive, this might take a few minutes.

(2) Remove the site's cookies (save any pending work first). While viewing a page on the site, try either:

• right-click (on Mac Ctrl+click) a blank area of the page and choose View Page Info > Security > "Clear Cookies and Site Data"
• (menu bar) Tools > Page Info > Security > "Clear Cookies and Site Data"
• click the padlock or "i" icon in the address bar, then the ">" button, then More Information, and finally the "Clear Cookies and Site Data" button

In the dialog that opens, you will see one or more matches to the current address so you can remove the site's cookies individually without affecting other sites.

Then try reloading the page. Does that help?

Testing in Firefox's Safe Mode: In its Safe Mode, Firefox temporarily deactivates extensions, hardware acceleration, and some other advanced features to help you assess whether these are causing the problem.

If Firefox is not running: Hold down the Shift key when starting Firefox. (On Mac, hold down the option/alt key instead of the Shift key.)

If Firefox is running: You can restart Firefox in Safe Mode using either:

• "3-bar" menu button > "?" Help > Restart with Add-ons Disabled
• (menu bar) Help menu > Restart with Add-ons Disabled

and OK the restart.

Both scenarios: A small dialog should appear. Click "Start in Safe Mode" (not Refresh).

Any improvement?

Thanks for your help. After the latest windows update i can finally see videos from YouTube which i have been unable to see for years. One wonders why it is so difficult to get to see the videos when most other platforms can accomplish this. Why so many work-arounds?

jwsr71 said

After the latest windows update i can finally see videos from YouTube which i have been unable to see for years. One wonders why it is so difficult to get to see the videos when most other platforms can accomplish this. Why so many work-arounds?

What workarounds did you need to use? On Windows, Firefox needs Media Foundation to decode MP3s and MP4s because as a matter of principle and probably also economics, Mozilla does not include those proprietary patented decoding technologies in Firefox. If Media Foundation is present when you install Firefox, and no add-ons or custom settings interfere after that, "it just works."