See separate Help installation instructions at http://helpx.adobe.com/creative-suite/kb/help-application-doesnt-update.html.
Adobe plans to offer PDF reference files for download in June 2012 and apologizes for the inconvenience. If you are encountering error messages, such as "Adobe Help Viewer is not available. Please reinstall the application," see the separate troubleshooting document: http://helpx.adobe.com/creative-suite/kb/help-manager-troubleshoot-error-codes.html
Online Help is updated and provides a comprehensive reference. Online Help for every Adobe product is available at http://helpx.adobe.com/support/
In most cases, there is no need to reinstall the CS product application or the Help Manager. The error strings are outdated and incorrect. See the troubleshooting document referenced above for more details and steps to resolution.
For especially large Help packages, the download process can take a long time. The application sometimes appears to be unresponsive or to have crashed.
In most cases, the download is completing properly. However, each download has two stages: a download stage and a decompression stage. Visual feedback is provided during the download stage in the form of a progress bar animation. During the decompression stage, no additional visual feedback appears. In some cases, the decompression stage can take longer than the download stage, especially if your hard disk is nearly full.
Note: You can cancel the download process by clicking the red X icon in the Local Content preferences panel of the Help Manager.
In some cases, the uncompressed local copy of a Help package can consume much space on your hard disk. This disk space consumption is due, in part, to the large number of files in each Help package.
To free some space on your hard drive, delete individual Help packages:
With the Accessibility Mode preference set to Open Help In Browser, selecting product Help does not open the Community Help application. Open the Community Help as a free-standing application to change the Accessibility Mode preference to Open Community Help Application.