Technical Notes

All COMET® Program lessons use JavaScript and some use Adobe® Flash® for navigation, animation, and/or presentation of multimedia elements. Ensure that you have enabled them in your web browser.

Before publishing a lesson, we test it on the latest Apple and Microsoft operating systems using most common web browsers (Google Chrome, Mozilla Firefox, Apple Safari, and Microsoft Internet Explorer 9 or greater). With these technologies constantly evolving, we cannot guarantee that all of our lessons will work on future browser releases or updates. We recommend that you always run the latest version operating system, browser, and plug-ins in order to avoid security and stability issues.

Common Flash Problems for Offline Viewing

If you download any of the COMET lessons, or access lessons on a CD/DVD, you may need to configure the Global Security Settings in the Adobe Flash Player to be able to utilize and navigate through the lesson. Please refer to the Flash Player Help page for details on how to configure the player for offline local media access.

Note: You MUST have an Internet connection to update your Flash settings as this problem can only be corrected while online with the Adobe Website.

Installing Flash

To install Flash, please visit the Adobe® Website to download and install the plug-in manually using the directions given.

Enabling Pop-Up Windows

Some lessons may link to external sources, which may open in another tab or pop-up window. If your internet browser blocks pop-up windows, some of these links may be blocked.  Exceptions can be configured within your browser to allow these pop-ups from and other trusted domains. Refer to the “Help” of your specific browser to configure these settings.

ActiveX Controls for Download and CD/DVD Archive Versions

Users of the download versions (and CD/DVD archives and special issue discs) of COMET lessons who choose to use the Internet Explorer browser on a PC will also need to configure Windows to allow ActiveX controls to run from the local hard disk (wherever you installed the download) or from the CD-ROM/DVD-ROM drive from which you are viewing archive discs.

If you do not allow this access, Flash-based Web lessons will not run. In a corporate or government computing environment, individual users may not have permission to change this setting unless they have "Administrator" level computer permissions. Individuals in those computing environments should coordinate this activity with management and/or their IT department. Refer to the Adjust Internet Explorer ActiveX settings page from Microsoft to adjust these settings in your browser.

If you are viewing this on a downloaded copy of the lesson, our most up-to-date technical support information is available at