How do I populate a dataGrid?

Question

Hello:
 
What I have found is that the code is suppose to be something like the following: (I think)
dataGridViewIP_Login.Rows[1].Cells["ProfileUser_ID"].Value = "aaaa";   // The '1' will be replaced with the row value later.
 
But it seems that it does not add the "aaaa" into the grid.
A few days ago, I was reading in a txt(csv) file and using it. Now I would like to load it into a dataGridView...use it and then write it back out to the txt(csv) file.I would like to use a database for this stuff I am doing, but I cant. Its a control record that I use to validate if the user can (be allowed) to the databases.
 
If anyone knows where I can get a sample code program, I appreciate it.