Hi Mudasser,
Based on your post, you want to create a DataGridViewComboBoxColumn with a horizontal scrollbar, don’t you? If so, you need to create your own combo box with the horizontal scrollbar. You can check this article. It has provided you how to give ComboBox a horizontal scrollbar. Then you need to host this ComboBox to your DataGridView cell. About how to host control in DataGridView cells, please check this page on MSDN.
· http://msdn2.microsoft.com/en-us/library/7tas5c80.aspx
Hope this helps.
Best regards.
Rong-Chun Zhang