I'm having trouble determining the proper procedure for installing Exchange 2007 sp3 on a Server 2008 R2 box running Exchange 2007 sp1.
It is not clear on websites I have consulted (Microsoft TechNet and others) whether preparing Active Directory is only required on a NEW install of Exchange 2007 sp3, or if it is required when upgrading an existing Exchange 2007 install to sp3.
Could someone who has experience with this please set me straight?