This “Hands On” session provides a first exploration of the Mozilla Platform and more steps that set up the NoteTaker project.
This book recommends downloading the 1.4 release of the platform, which includes Classic Mozilla and the platform. Later releases are also probably fine. You might want to check www.nigelmcfarlane.com for recent updates if this book has been in print a while.
The installation notes on mozilla.org are quite complete and should be read for your platform. They can be reviewed from the official download pages. Some less obvious effects are briefly covered here.
On Windows 95/98/Me, your user profile will be installed in this obscure location: