If you cannot view your lists in Datasheet view and see this message instead:
The list is displayed in Standard view. It cannot be displayed in Datasheet view for one or more of the following reasons:
- A datasheet component compatible with Windows SharePoint Services is not installed;
- Your browser does not support ActiveX controls;
- Support for ActiveX controls is disabled.
It means that your local computer does not have Microsoft Office 2003 installed, which is necessary for viewing lists in Datasheet view. Neither Office 2000 nor Office XP are compatible with SharePoint 2003.