'Otra de espacio libre del disco duro
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

Public Type DiskInformation
    lpSectorsPerCluster As Long
    lpBytesPerSector As Long
    lpNumberOfFreeClusters As Long
    lpTotalNumberOfClusters As Long
End Type

'en cualquier parte del programa
Dim info As DiskInformation
Dim lAnswer As Long
Dim lpRootPathName As String
Dim lpSectorsPerCluster As Long
Dim lpBytesPerSector As Long
Dim lpNumberOfFreeClusters As Long
Dim lpTotalNumberOfClusters As Long
Dim lBytesPerCluster As Long
Dim lNumFreeBytes As Double
Dim sString As String

lpRootPathName = "c:\"
lAnswer = GetDiskFreeSpace(lpRootPathName, lpSectorsPerCluster, lpBytesPerSector, lpNumberOfFreeClusters, lpTotalNumberOfClusters)
lBytesPerCluster = lpSectorsPerCluster * lpBytesPerSector
lNumFreeBytes = lBytesPerCluster * lpNumberOfFreeClusters
sString = "Number of Free Bytes : " & lNumFreeBytes & vbCr & vbLf
sString = sString & "Number of Free Kilobytes: " & (lNumFreeBytes / 1024) & "K" & vbCr & vbLf
sString = sString & "Number of Free Megabytes: " & Format(((lNumFreeBytes / 1024) / 1024), "0.00") & "MB"

MsgBox sString