You cannot view a list in Datasheet view on a SharePoint website after you install the 64-bit version of Microsoft Office 2010.
When you click Actions and then click Edit in Datasheet on a SharePoint 2003 or 2007 site, or you click the List tab and then click Datasheet view on a SharePoint 2010 site, you receive the following error message:
The list cannot be displayed in Datasheet view for one or more of the following reasons:
- A datasheet component compatible with Microsoft SharePoint Foundation is not installed.
- Your Web browser does not support ActiveX controls.
- A component is not properly configured for 32-bit or 64-bit support.
Here is the link to the Microsoft support.