The new DataGridView control doesn't have a Cells collection, but it has Rows,Columns and a default indexer.
To set the value of a certain cell in the DataGridView, it is easy to use the indexer like this:
dataGridView1[1,1].Value = "New Value";
Or, we can do that using the Rows collection:
Rows.Cells.Value = "New Value";
For more information about the DataGridView see those links: