Option Explicit
 
Private Sub Command1_Click()
    Dim ff As Integer
 
    On Error Resume Next
 
    ff = FreeFile
    Open "K:\win_anw\vb50\ihv\ihv.exe" For Binary Lock Read Write As #ff
    If Err.Number = 0 Then
        MsgBox "not in use", vbInformation
        Close ff
    ElseIf Err.Number = 70 Then
        MsgBox "in use", vbCritical
    Else
        MsgBox "anderer Fehler:" + vbCr + Err.Description, vbCritical
    End If
End Sub

Gru? Michi aus Hannover

1 + 1 = 3 f?r hinreichend gro?e 1