I have a data set and I want to know whether it is Normally distributed or not. How can I do this easily? I would prefer to be able to do it in Excel as I don't have any advanced statistical packages like SPSS.

Just keep in mind that you can't "prove" or say "yes" or "no" if the question is asked: "Is the data normally distributed?"

What you can say is whether or not there is enough evidence, either visually or through a test, to say that the sample data "probably did not" come from a normally distributed population.

You might also consider a relatively inexpensive Excel add-on like Analyse-It that can do some simple procedures, such as tests for normality.