Error installing Exchange Service Pack 2

Hi,

After actioning all the required prerequisites I encountered the below issue,

[ERROR] Setup previously failed while performing the action "Uninstall".  You can't resume setup by performing the action "BuildToBuildUpgrade"

There are a number of websites stating different reasons on why this can happen but I’m yet to find a direct response or help from any Microsoft KB.

If anyone can please provide me with a resolution or a path going forward that would me great.

System Setup;

Windows Server 2008 R2 SP1

Exchange Server 2010 SP1 Rollup 5

Thanks