How to install html5 on Windows XP to play videos on Mozilla?

[WaterBubble]

I know my OS is old. But it works fine on my old computer. Recently I found that lots of sites with video, for example Youtube live stream, tend to use html5, my Mozilla refuses to play it, I wrote them and they said I have to install html5 support on WinXP. But how to install?? Someone advised Primetime html5 content decryption module. But it's not supported by Adobe anymore. So is there other way to make my Mozilla on Windows XP play html5 videos?

[japygy]

Firefox works on Windows XP SP2 (and SP3) all the way to Windows 10. However Firefox 53.0 and later will be dropping WinXP and Vista support. WinXP and Vista users can use the then Firefox 52 ESR for security updates for a while still as the 52.8.0 ESR will be out when Firefox 60.0 is released.

[DaveLembke]

Friend of mine is using Google Chrome browser on a Pentium 4  2.6Ghz running XP Home SP3 on 1GB RAM with NVidia GeForce 6200 AGP Video card with 256MB RAM and HTML 5 videos etc are playing ok on it on 1024 x768 resolution. So if you run into troubles with Firefox you could try Chrome Browser.

[patio]

Firefox works on Windows XP SP2 (and SP3) all the way to Windows 10. However Firefox 53.0 and later will be dropping WinXP and Vista support. WinXP and Vista users can use the then Firefox 52 ESR for security updates for a while still as the 52.8.0 ESR will be out when Firefox 60.0 is released.

The support issue is unrelated...mostly security issues FFox should still function fine on XP.

The HTML5 addon is available at the extensions page.
He went to the wrong source for HTML5.

[Geek-9pm]

A possible alternative would be SeaMonkey.
SeaMonkey will play some videos the older Firefox can not.

[patio]

Sea Monkey builds follow FFox builds...just so you know.

[Geek-9pm]

Patio, for some reason SeaMonkey works on XP on Amazon video. But recent versions of Firefox Amazon will block. Anybody's guess why the pick on Firefox and let SeaMonkey go in. Amazon says it is the 'unsupported OS'. Strange mystery. That would lead one to think that either SeaMonkey upgrades the  OS or does not tell Amazon it is XP.