First, create your HTML file and place it in whatever folder is easiest for you to remember. ( I have a folder on my D drive called Desktop Toolbars. )
Go to: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\AboutURLs
Create a new String Value with an easy to remember name.
Ex: TopToolbar ,BottomToolbar ,GoogleSearchPage
In the data for the new string value you've created, put the COMPLETE address for the HTML page you want to display in a toolbar.
Like this: D:\Desktop_Toolbars\TopBar.html
To show your new toolbar, right-click on your taskbar and choose "Toolbars" > New Toolbar.
In the box labeled Folder:, type about: with the name of the string value you created that represents the HTML file you want to see in your toolbar.
Like this:
about:TopBar
will display your D:\Desktop_Toolbars\TopBar.html in your taskbar.
about:BottomBar
about:GoogleSearchPage
See this screenshot for a visual example of something simple you can do