Error on installing Cumulative update package 2 for SQL Server 2008 Service Pack 1

I'm trying to install a hotfix for SQL Server 2008 SP1 on my Windows  server 2008 . When running the hotfix I keep on getting the following error message:

TITLE: SQL Server Setup failure.

A failure was detected for a previous installation, patch, or repair during configuration for features [SQL_BooksOnline_Redist,]. In order to apply this patch package (KB970315), you must resolve any issues with the previous operation that failed. View the summary.txt log to determine why the previous operation failed.

Error code 0x84B20001.