You don't need to use com interop to read from an Excel file. You can use OleDb (although you might need to install the office data connectivity components)
Imports System.Data.OleDb:
Public Shared Function ReadExcelWorkSheet(ByVal sheetName As String, ByVal connectionString As String) As DataTable
Dim sql As String = String.Format("SELECT * FROM [{0}$]", sheetName)
Dim dt = New DataTable()
Using conn As OleDbConnection = New OleDbConnection(connectionString)
Using cmd = New OleDbCommand(sql, conn)
conn.Open()
Using adapter = New OleDbDataAdapter(cmd)
adapter.Fill(dt)
End Using
End Using
conn.Close()
End Using
Return dt
End Function
Where connection string is for xlsx files:
Provider=Microsoft.ACE.OLEDB.12.0;Data Source=c:\myFolder\myExcel2007file.xlsx;Extended Properties="Excel 12.0 Xml;HDR=YES";
or for xls files:
Provider=Microsoft.ACE.OLEDB.12.0;Data Source=c:\myFolder\myOldExcelFile.xls;Extended Properties="Excel 8.0;HDR=YES";
more info on the connection strings here