Plug-ins added without my awareness

[curious]

Hi -

When I started Ff today I received a warning about MetaStream 3 possibly being harmful. I okayed it's being disabled.
Since I didn't know how that was added to the plug-ins, I went to see what else was there and found a couple for Netscape, which I disabled, one for Quick Time, for Shockwave Flash, for Microsoft DRM, for Windows Media Player which, since I used Windows Media I'm assuming (uh-oh) it's all right, 2 specifically for Mozilla (default and Foxit Reader).

When a plug-in is listed, how does it get there and how necessary are they?

Thank you, Curious

[TonyE]

On startup Firefox scans for plugins using several methods.

It will look for some common plugins such as Java and Acrobat/Reader in their installation directories.
It will check the registry for plugins. Quite a few plugins will add a registry key in the following location to inform Firefox that there is a plugin available.
HKEY_LOCAL_MACHINE\SOFTWARE\MozillaPlugins
It will check for any plugins that have been added to the Firefox plugins folder, default location C:\Program Files\Mozilla Firefox\plugins

You may never use quite a few of the plugins that are installed, and there is no problem in disabling them. The only plugin that is part of the Firefox installation is the one called Mozilla Default Plug-in.

[curious]

Tony -

sorry for the delay in thanking you but I just saw your response today.

Curious