importing data from excel to comboBox

Two common causes are visible in this thread. As @Hamrick noted, leaving DisplayMember unset produces list entries that show as "System.Data.DataRowView" because each item is a DataRowView. When two ComboBoxes end up showing the same values the usual culprits are: binding both controls to the same shared view or BindingSource and then changing the binding elsewhere; accidentally shadowing the designer control with a local declaration (for example declaring a new variable with the same name inside a method); or using the wrong column name (extra spaces or misspelling).

A reliable pattern is to build a one‑column DataTable (or a separate DataView) for each ComboBox so each list is independent:

' create a one-column table from an existing DataTable (excelTable)
Dim listTable As New DataTable()
listTable.Columns.Add("Text", GetType(String))
For Each r As DataRow In excelTable.Rows
    listTable.Rows.Add(If(r.IsNull("Iso Standards"), "", r("Iso Standards").ToString()))
Next

cbIso.DataSource = listTable
cbIso.DisplayMember = "Text"
cbIso.ValueMember = "Text"

To bind only the first row via OLEDB use a provider query such as:
SELECT TOP 1 [Iso Standards] FROM [Sheet1$]
Also check HDR in the connection string (HDR=Yes treats the first Excel row as column names). Quick checklist: enumerate DataTable.Columns to confirm exact column names, remove any local Dim ComboBox2 As ComboBox that hides the designer control, trim whitespace in column names, and use a separate BindingSource or DataView per ComboBox when independent lists are required. For heavier Excel work the Excel object model (as @shikeb mentioned) or a library like Open XML SDK can be used instead of OLEDB.