<hr>It is not all of the .avi file l want to rotate, but part of it , will Movie Maker allow me to do this? <hr>
Yes, the general process is to import the file into a project, split it into clips and then reassemble on the 'timeline' at the bottom of the screen. From the Timeline you then select the clip that needs rotating and apply the 'video effect' to rotate just that part.
From the link in Leif's post ( repeated here ) you'll see that it needs at least XP SP2, so If you don't have it already you may not be able to run it anyway.