Msg#: 3975744 posted 4:54 pm on Aug 20, 2009 (gmt 0)
I'm not a lawyer, but my understanding of "Fair Use" is that if the screenshot is transformative and limited, you should be okay. If you're writing a lesson on how to execute a certain process in Excel, for instance, then a few screenshots to illustrate the process should be fine.
(Of course, it never hurts to post a notice, somewhere in your "fine print", that you are not affiliated with Microsoft, are not endorsing Excel, yadda, yadda, yadda.)
As long as the majority of the material is your own original content (being, for the purposes of this example, a "how to" article), you should be fine.