While running reports if Backup Exec detects Acrobat Reader, it opens the report in Acrobat. Please verify if you are able to view reports in HTML format by uninstalling Acrobat Reader. If it outputs the report in HTML then try reinstalling Acrobat and run reports again. If the issue persists, please let us know the following:
1. Does that happen with a specific report or it happens with all the reports that you run?
You can also try upgrading your acrobat reader to the latest version.