Windows Service Pack 3 freezes when you get to “Running Processes After Install”.

When you are installing Service Pack 3, you might encounter a problem where the installation freezes when you get to “Running Processes After Install”.

When that happens Open up task manager (pressing Ctrl+Alt+Del) click on the process tab and select the process “shmgrate.exe”, this process for some reason stops the Service Pack 3 from completing the install.