What you probably downloaded was the PowerPoint Viewer (free), not the
full version of PowerPoint (costs money). You will have to buy a legal
copy of PowerPoint in order to edit (although I believe Microsoft has a
30-day test-drive available for PowerPoint 2003). If you do have the full
version of PowerPoint, start up PowerPoint and choose Open from the File
menu to open the file (it might be .pps, which automatically opens in
Show mode).
--David
--
David M. Marcovitz
Director of Graduate Programs in Educational Technology
Loyola College in Maryland
Author of _Powerful PowerPoint for Educators_
http://www.loyola.edu/education/PowerfulPowerPoint/