How I Create Videos Using Free Tools - Using Movie Maker
Landing page for this series of how-to is here How I Create Videos Using Free Tools
Here is the simplest way I found to concatenate couple of static slides:
1. Create image files, for example using Paint

2. Drag and drop it on Movie Maker surface:
3. While in Movie Maker drag and drop it on Video lane:
4. Optionally add transitions - I usually skip this one since it inflates the size of the resulting WMV file
5. Create the video by clicking this:
6. Specify destination folder and file name and click next:
7. Accept default settings and then click "Publish" button:
8. Done:
Enjoy