After you have installed Service Pack 3 (SP3) on your SharePoint Portal Server 2003 and try to use the “Edit in Datasheet” feature, you may receive the following error message:
“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, or support for ActiveX controls is disabled.”
Google this on the internet and you will find most solution containing instructions about the Microsoft Office 2003 Professional Edition. Some may be work around like changes in the Registry.
If this problem is on the server, it is desirable to visit the following link on Microsoft site and take appropriate actions based upon your own risk analysisL.