“Setup Wizard for Update Rollup 3 for Exchange Server 2010 (KB981401) ended prematurely because of an error. Your system has not been modified. To install this program at a later time, please run the installation again.”
In my case this turned out to to be a User Account Control (UAC) gotcha. Basically, I didn’t launch the *.msp file using “Run as Administrator”. Interestingly, the error is misleading in that it does modify the system. If you look at the installed updates on the system the Update Rollup appears as being installed. In other words it is partly installed.
The steps to resolve the issue are:
1. Go to Control Panel, Programs, Programs and Features, Installed Updates. Highlight the update and then click Uninstall.
2. Open a CMD prompt using right-click “Run as Administrator”. Browse to the folder where the file is located and launch the file named Exchange2010-KB981401-x64-en.msp.
One of these days I’m really going to get the hang of UAC 🙂 . Until I do, it would be really nice if the Microsoft product teams could provide more helpful error messages for UAC failures.