I can find the procedure for 2013 http://technet.microsoft.com/en-us/library/bb125224.aspx
But don’t seem to be able to find the one for 2010 at technet. But I am assuming that if I already have Exchange 2003SP2 running in my environment, then I can just run setup.com /prepareAD (without the organizationaname switch), to extend the schema.
But can I do this several days before I actually install Exchange 2010? Lets say I perform this on the first of a month, and then install Exchange 2010 on the 15th of that same month, so for two weeks I will be running Exchange 2003SP2, but I will have extended the schema.
Can that lead to problems with the existing Exchange 2003SP2 environment?
Forget to add, its a single forest, single domain, single site AD.