I don’t know how many of you know about this but I certainly didn’t
When you download the source of base4 which you can find here
And you navigate to the folder C:\Program Files\Base4 Solutions Ltd\Base4 version 2.1\Source**Base4.Storage\Resources**
Or whereever you installed the source and copy the xsd file that is there to the folder C:\Program Files\Microsoft Visual Studio 8**Xml\Schemas** (the folder xml schemas in your visual studio install dir)
When you restart/start visual studio now and you want to edit a schema now the things popup to assist you
Don’t forget to register on the base4 site if you haven’t already.