Where does Internet Explorer store its' add-ons?

Question

I have checked all around the registry and I could not find any lists of all installed extensions.

At this point, any general location of IE extensions/add-ons would help.

Answer 1

Taken from here:

Browser Helper Objects - Browser plug-ins which are designed to enhance the browser's functionality. Entries can be found in the registry at:

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Explorer\Browser Helper Objects

Toolbars - Additional toolbars that appear in a browser, often below the address bar. Entries can be found in the registry at:

HKEY_LOCAL_MACHINE\Software\Microsoft\Internet Explorer\Toolbar

URLSearchHooks - Used when an address without a protocol such as http:// has been entered in the browser's address bar. Entries can be found in the registry at:

HKEY_LOCAL_MACHINE\Software\Microsoft\Internet Explorer\URLSearchHooks

Explorer Bars - Internet Explorer sidebars located adjacent to the browser pane. Entries can be found in the registry at:

HKEY_LOCAL_MACHINE\Software\Microsoft\Internet Explorer\Explorer Bars
HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Explorer Bars

Additionally, custom items for context menu:

HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\MenuExt\<Menu Text>
HKEY_LOCAL_MACHINE\Software\Microsoft\Internet Explorer\MenuExt\<Menu Text>

Custom items for Tools menu, custom toolbar buttons:

HKEY_LOCAL_MACHINE\Software\Microsoft\Internet Explorer\Extensions\{GUID}

More info on MSDN.