You can obtain CAST Architecture Checker from the ExtendNG. Search for "architecture checker" and choose the CAST Architecture Checker option:
A ZIP file will be downloaded - unpack this ZIP file and proceed as described
You can obtain the CAST Report Generator from the CAST Product Center - this requires a CAST login. A ZIP file will be downloaded - unpack this ZIP file and proceed as described in Installation steps.
Double click the executable file. Click Yes, when prompted to allow the installation.