linq query, datagridview

[Fangling]

hi i have these codes:

  Dim dt As New DataTable

                        ' Create four typed columns in the DataTable.
                        dt.Columns.Add("ConflictingPaper", GetType(String))
                        dt.Columns.Add("Numberofstudents", GetType(Integer))
                        dt.Columns.Add("AdminNo", GetType(String))

                        Dim query1 = (From a In dt3 Group CStr(a.Field(Of Integer)("PaperNo")) By AdminNo = (a.Field(Of String)("AdminNo")) Into Group Select dt.LoadDataRow(New Object() {String.Join(":", Group.ToArray()), Group.Count(), AdminNo}, False)).ToList().Count()

                        DataGridView3.AutoGenerateColumns = True
                        Me.DataGridView3.DataSource = dt

aiming to populate:

Conflictinglist    numofstudents   adminno
12:26              2               111411H
                                   298291Y
2:4                4               292918J
                                   102938S
                                   192838A
                                   292837V
.
.
.

populating it in datagridview.
but my codes are some some errors which ican't seemed to solve.
Above code is using linq query.
When program is run, the form sort of hang, my data is not populated out.

Please help me with the codes! thanks!