A few properties of the VB6DataGrid – most notably, the DataSource, DataMember, HelpContextID, and WhatsThisHelpID properties – appear grayed in the property window and can’t be modified.
This issue isn’t limited to the DataGrid control and appears to be common to all controls that inherit from an ActiveX control (or, equivalently, from the AxHost managed class): only properties that are exposed in the original control and that are not overridden can be modified as usual in the property window.
To work around this issue, VB Migration Partner stores these values inside the control’s Tag property. This approach is used for all controls that inherit from an ActiveX control, such as VB6DataGrid and VB6MMControl. For example, the Tag property of a VB6DataGrid might read as follows:
Once you know this detail it’s quite easy to modify the value of these properties at design time. (Remember to be careful not to accidentally delete or alter the value of the Tag property when you do it.)