ADOVBS.inc doesn't give you the funtionality of ADO, it allows you to use ADO constants without having to declare them yourself. If you look in this file all it does is declare constants. This file is included into your own asp page when the asp page is requested by a user.
A far better solution than using this include file is to use the COM component. You can place this in your global.asa file and then you would not need to include it in all your pages otherwise place this at the top of the pages you need it. Note, you may need to change the path. Ask your system administrator where this dll is located if you do not have access to the server.
<!-METADATA TYPE="typlib" FILE="C:\Program Files\Common Files\system\ado\msado15.dll" -->
Don't worry about the name of the dll. 15 is not the version.
One other note. Consider changing the extension of your include files to .asp instead of .inc. Your web server will not show the contents of a .asp file but it will for a .inc file. If a user types in the URL of your .inc file they can see the contents of it. You can setup IIS not to show the contents of a .inc file but it is much easier to just use .asp as the extension.
Hope this helps,
Gabe