When you try to apply the Update rollup 1 for Exchange Server 2010 and have UAC on (like you really should have) you may see the following message: "Setup Wizard for Update Rollup1 for Exchange Server 2010 (KB976573) ended prematurely".
If this problem shows up try the following steps:
- Find the command prompt on the start menu
- Right click on the icon and select Run as administrator
- Browse to the directory where the patch is located
- Run the patch