Apply the Exchange Service Pack
Apply the Exchange Service pack. It must be the most recent Exchange Service Pack that was installed on the original computer. Insert the SP DVD or have ready the downloaded file for the Exchange Service Pack.
Open an administrative console and run SETUP.EXE or UPDATE.EXE to install the Exchange Service Pack.
Do not reboot yet.
Install post-SP fixes
Finally, install any post-SP rollup packs or hotfixes.
At this point Exchange should have the same service pack and hotfixes as the source computer. This brings Exchange up to the same revision level as the source computer. Finally, reboot the computer.
Congratulations! You are now ready to move AD and Exchange to the new computer.
Next step: Move AD and the Exchange Database
|U-Move for Active Directory|