You can download DCS97 from the DCS97 support site at http://support.sperryrail.com/dcssupport .
The full install download can be found under the downloads section at
the bottom of the page. Click the full install link to download the
install zip file.
or, click this link > http://support.sperryrail.com/DCSsupport/DCSfiles/03Install.zip
and use the above username and password combination to download the file.
This file will need to be extracted to a folder on your computer. Once extracted locate and double left click on the "Setup.exe" file. This will run the install of DCS97.