Cause.
Setup program found the Reporting Services Catalog database file and Reporting Services Catalog temporary database file in the following path:
C:Program FilesMicrosoft SQL ServerMSSQL10.MSSQLSERVERMSSQLDATA
Solution.
Remove the following files from the "C:Program FilesMicrosoft SQL ServerMSSQL10.MSSQLSERVERMSSQLDATA" directory:
bulletReportServer.mdf
bulletReportServer_log.LDF
bulletReportServerTempDB.mdf
bulletReportServerTempDB_log.LDF.
After deleting the files, click on the "Re-run" button of the Installation Rules setup page, and click "Next" after passing all the installation rules.