Code:
Private Sub Timer1_Timer()
 On Error Resume Next
 Static HH As Single
 Static MM As Single
 Static SS As Single
 Static TS As Single
 Static TSS As Single

 TS = TS + 1
 
 TSS = TS / 10
 
 If TSS = ".9" Then
   TS = 0
   SS = SS + 1
   
   If SS = "59" Then
     SS = 0
     MM = MM + 1
     
     If MM = "59" Then
       MM = 0
       HH = HH + 1
     End If
   End If
 End If
 
 Label5.Caption = Right("00" & HH, 2) & ":" & _
                  Right("00" & MM, 2) & ":" & _
                  Right("00" & SS, 2) & ":" & _
                  Right("00" & TS, 2)
 
End Sub