Private Declare Function SetComputerNameAPI Lib "kernel32" Alias _
  "SetComputerNameA" (ByVal lpComputerName As String) As Boolean
 
    Public Function SetComputerName(ByVal ComputerName As String) As Boolean
        SetComputerName = (SetComputerNameAPI(ComputerName) <> 0)
    End Function

  Private Sub cmdOK_Click(sender As System.Object, e As System.EventArgs) _
    Handles cmdOK.Click
        If SetComputerName(txtNewComputername.Text.ToString) = True Then
            MsgBox("OK")
        Else
            MsgBox("nicht OK")
        End If
    End Sub

    Sub ChangeComputerName(ByVal NewHostName As String)
        Dim myPath As New ManagementPath
        myPath.Server = System.Net.Dns.GetHostName
        myPath.NamespacePath = "root\CIMV2"
        myPath.RelativePath = "Win32_Computersystem.Name='" & myPath.Server & _
          "'"
        Dim myObj As New ManagementObject(myPath)
        Dim myParams() As Object = {NewHostName}
        myObj.InvokeMethod("Rename", myParams)
    End Sub