Code:
Option Explicit
Private Declare Function GetDiskFreeSpace Lib “kernel32″ Alias _
“GetDiskFreeSpaceA” (ByVal lpRootPathName As String, _
lpSectorsPerCluster As Long, lpBytesPerSector As Long, _
lpNumberOfFreeClusters As Long, lpTtoalNumberOfClusters As Long) As Long

Private Sub Command1_Click()
Dim Sectors As Long, Bytes As Long, FreeC As Long, TotalC As Long, Total
...