Yes Im happy that Excel is on the machine and that the right version is being used.

I also went through this documentation

http://social.msdn.microsoft.com/forums/en-US/sqlintegrationservices/thread/8b52557b-cd13-4db6-87b6-230b7e051a9e/

http://www.microsoft.com/en-us/download/confirmation.aspx?id=227

http://www.databasejournal.com/features/mssql/article.php/3921141/SSIS-Script-Task-and-Microsoft-Office-Automation.htm

to ensure the correct Excel object is referenced.

oIf you are automating Microsoft Office Excel 2007, the type library appears as Microsoft Excel 12.0 Object Library in the References list.

oIf you are automating Microsoft Office Excel 2003, the type library appears as Microsoft Excel 11.0 Object Library in the References list.

oIf you are automating Microsoft Excel 2002, the type library appears as Microsoft Excel 10.0 Object Library in the References list

oIf you are automating Microsoft Excel 2000, the type library appears as Microsoft Excel 9.0 Object Library in the References list.

oIf you are automating Microsoft Excel 97, the type library appears as Microsoft Excel 8.0 Object Library in the References list

So Im happy with all that.