Right click one of the squares in the chart
Select Format Data Series from popup menu
Right side of dialog: click Marker Options
Click Build-In and select your shape and size
To change colour: Marker Fill, then Solid Fill and select colour needed

best wishes
--
Bernard Liengme
http://people.stfx.ca/bliengme
Microsoft Excel MVP

"Bob" wrote in message
...
Hello,

Using Excel 2007

I'm embarrassed to ask this, as it's undoubtedly so simple, but just can't
find out how to do it.

Everything sure was simple in earlier versions !

Anyway, I have a simple chart that I created, linear, with the data points
being shown as squares. Guess it picked the squares on its own,
automatically.

I would like to change them to circles, and also their size.

How do do this, please ?

Thanks,
Bob