Blocked help

Oh it is such a joy to use Microsoft based technologies. Needed a Sitecore (A .Net based web content management system) API reference. So far as I could see it was only available on their developers network as a Windows help file. Download file. Double click. Can't view contents. Need to go back on the web and search to discover that you need to go back into the properties of the help file and click "Unblock". Nowhere does Microsoft make that obvious. If I were using an open source CMS then the APIs would probably be in nice searchable and commented HTML files easily available on the web.