I've heard from several Captivate 5 developers that they do not have the Adobe Captivate Reviewer 2.0 on their systems. That's strange because the Reviewer is usually installed when you install Captivate 5.
If the installer is not on your system, you'll find that the download link isn't easy to find via a Google search. In that case, here is a direct link to download the installer. (Don't say I never do nuttin for ya!)
FYI: You'll need the Adobe Captivate Reviewer 2.0 application to open Captivate Review Files (CREV's) and send comments back to the Captivate developer via Acrobat.com, which is wicked cool. When you send CREV's to reviewers from within Captivate, the link above is included in the email that your reviewers will open (you won't have to manually send the link to reviewers).