After installing SP2 on SQL Server 2005 x64, when trying to open existing SSIS package or try to add data component to a new SSIS package, is giving error saying that designer could not be initialised.

After installing SP2 on SQL Server 2005 x64, when trying to open an existing SSIS package or trying to add data component to a new SSIS package, you may receive an error saying that the designer could not be initialised.
This problem occurs because the installer unregisters the 32-bit Dts.dll file when the installer installs the 64-bit Dts.dll file. The 64-bit Dts.dll file is installed together with SQL Server 2005 SP2. Additionally, the 64-bit Dts.dll file may be installed together with any SSIS hotfix package that contains the 64-bit Dts.dll file.
Solution 1: Un-install SQL Server 2005 client tools and reinstall it again.
Solution 2: Register dts.dll
%windir%\syswow64\regsvr32 "%ProgramFiles(x86)%\Microsoft SQL Server\90\dts\binn\dts.dll"