Microsoft Exchange Server 2007 SP2 Installation Tool for Windows SBS 2008
http://www.microsoft.com/downloads/details.aspx?FamilyID=ffd2fe61-9278-489e-9b96-3816394c9cb6&displayLang=en
If you didn’t have this tool you’d have to do this.
Download Exchange 2007 SP2
http://www.microsoft.com/downloads/details.aspx?FamilyID=4C4BD2A3-5E50-42B0-8BBB-2CC9AFE3216A&displaylang=en
How to install Exchange 2007 SP2 on SBS2008 without tool
http://support.microsoft.com/default.aspx?scid=kb;EN-US;973862
