If the API documentation opens and looks like this:
Windows is blocking the .chm file. You can disable this by right clicking on the .chm file, going to properties, and clicking 'Unblock.'
Similarly, the precompiled library
in .zip format may be blocked. This can cause problems when attempting to reference the .dlls in a project depending on the security configuration. The .zip file can be unblocked in the same way by right clicking, going to properties, and clicking