By default this feature does not start until after you log on. But with the tweak below you will be able to make it start as windows loads so it will be enabled on the welcome login screen.
Start regedit, if you are unfamiliar with regedit please see our FAQ.
Navigate to HKEY_USERS\.DEFAULT\Control Panel\Desktop.
Locate the key FontSmoothingType.
Change the value to 2.