Note: These titles will work in WMM 2.1 (XP) and WMM 6.0 (Vista). I've provided XML for both versions in the installers.
There are two installers depending on whether you are running on a 32-bit or 64-bit version of Windows. The installer will put the necessary files into, C:\Program Files\Movie Maker\Shared.
Go to 'Tools' > 'Titles and Credits' > 'Title on the selected clip'.
Click on 'change the title animation'.
Under your list of one line titles should be two titles:
Choose the one that matches your project, then click 'Done'.
Stretch the title so that it extends for the length of your video.