Hello Ms Tina,
Have you downloaded the Project 2007 trial? Have you installed it?
If you're having trouble with the IMG file, you'll need to extract the
image to a format which your machine can read. See the following
details. Although it references a different software img file, the
steps should still work.
http://tinyurl.com/4jq9xa
The above link is to the codeplex site and details how to install from
an img file.
I hope this helps. Let us know how you get along.
Julie
Project MVP
Visit
http://project.mvps.org/ for the FAQs and additional information
about Microsoft Project