'Example by Alexey (alexeyka2001@rambler.ru)
Private Const DRIVE_UNKNOWN = 0
Private Const DRIVE_ABSENT = 1
Private Const DRIVE_REMOVABLE = 2
Private Const DRIVE_FIXED = 3
Private Const DRIVE_REMOTE = 4
Private Const DRIVE_CDROM = 5
Private Const DRIVE_RAMDISK = 6
' returns errors for UNC Path
Private Const ERROR_BAD_DEVICE = 1200&
Private Const ERROR_CONNECTION_UNAVAIL = 1201&
Private Const ERROR_EXTENDED_ERROR = 1208&
Private Const ERROR_MORE_DATA = 234
Private Const ERROR_NOT_SUPPORTED = 50&
Private Const ERROR_NO_NET_OR_BAD_PATH = 1203&
Private Const ERROR_NO_NETWORK = 1222&
Private Const ERROR_NOT_CONNECTED = 2250&
Private Const NO_ERROR = 0


Private Declare Function WNetGetConnection Lib "mpr.dll" Alias _
        "WNetGetConnectionA" (ByVal lpszLocalName As String, _
        ByVal lpszRemoteName As String, cbRemoteName As Long) As Long
Private Declare Function GetLogicalDriveStrings Lib "kernel32" Alias _
    "GetLogicalDriveStringsA" (ByVal nBufferLength As Long, _
    ByVal lpBuffer As String) As Long
Private Declare Function GetDriveType Lib "kernel32" Alias "GetDriveTypeA" _
    (ByVal nDrive As String) As Long
Private Function fGetDrives() As String
'Returns all mapped drives
    Dim lngRet As Long
    Dim strDrives As String * 255
    Dim lngTmp As Long
    lngTmp = Len(strDrives)
    lngRet = GetLogicalDriveStrings(lngTmp, strDrives)
    fGetDrives = Left(strDrives, lngRet)
End Function
Private Function fGetUNCPath(strDriveLetter As String) As String
    On Local Error GoTo fGetUNCPath_Err


    Dim Msg As String, lngReturn As Long
    Dim lpszLocalName As String
    Dim lpszRemoteName As String
    Dim cbRemoteName As Long
    lpszLocalName = strDriveLetter
    lpszRemoteName = String$(255, Chr$(32))
    cbRemoteName = Len(lpszRemoteName)
    lngReturn = WNetGetConnection(lpszLocalName, lpszRemoteName, _
                                       cbRemoteName)
    Select Case lngReturn
        Case ERROR_BAD_DEVICE
            Msg = "Error: Bad Device"
        Case ERROR_CONNECTION_UNAVAIL
            Msg = "Error: Connection Un-Available"
        Case ERROR_EXTENDED_ERROR
            Msg = "Error: Extended Error"
        Case ERROR_MORE_DATA
               Msg = "Error: More Data"
        Case ERROR_NOT_SUPPORTED
               Msg = "Error: Feature not Supported"
        Case ERROR_NO_NET_OR_BAD_PATH
               Msg = "Error: No Network Available or Bad Path"


        Case ERROR_NO_NETWORK

               Msg = "Error: No Network Available"
        Case ERROR_NOT_CONNECTED
               Msg = "Error: Not Connected"
        Case NO_ERROR
               ' all is successful...
    End Select
    If Len(Msg) Then
        MsgBox Msg, vbInformation
    Else
        fGetUNCPath = Left$(lpszRemoteName, cbRemoteName)
    End If
fGetUNCPath_End:
    Exit Function
fGetUNCPath_Err:
    MsgBox Err.Description, vbInformation
    Resume fGetUNCPath_End
End Function


Private Function fDriveType(strDriveName As String) As String
    Dim lngRet As Long
    Dim strDrive As String
    lngRet = GetDriveType(strDriveName)
    Select Case lngRet
        Case DRIVE_UNKNOWN 'The drive type cannot be determined.
            strDrive = "Unknown Drive Type"
        Case DRIVE_ABSENT 'The root directory does not exist.
            strDrive = "Drive does not exist"
        Case DRIVE_REMOVABLE 'The drive can be removed from the drive.
            strDrive = "Removable Media"
        Case DRIVE_FIXED 'The disk cannot be removed from the drive.
            strDrive = "Fixed Drive"
        Case DRIVE_REMOTE  'The drive is a remote (network) drive.
            strDrive = "Network Drive"
        Case DRIVE_CDROM 'The drive is a CD-ROM drive.
            strDrive = "CD Rom"
        Case DRIVE_RAMDISK 'The drive is a RAM disk.
            strDrive = "Ram Disk"
    End Select
    fDriveType = strDrive
End Function


Sub sListAllDrives()
    Dim strAllDrives As String
    Dim strTmp As String
    
    strAllDrives = fGetDrives
    If strAllDrives <> "" Then
        Do
            strTmp = Mid$(strAllDrives, 1, InStr(strAllDrives, vbNullChar) - 1)
            strAllDrives = Mid$(strAllDrives, InStr(strAllDrives, vbNullChar) + 1)
            Select Case fDriveType(strTmp)
                Case "Removable Media":
                    Debug.Print "Removable drive :  " & strTmp
                Case "CD Rom":
                    Debug.Print "   CD Rom drive :  " & strTmp
                Case "Fixed Drive":
                    Debug.Print "    Local drive :  " & strTmp
                Case "Network Drive":
                    Debug.Print "  Network drive :  " & strTmp
                    Debug.Print "       UNC Path :  " & _
                                fGetUNCPath(Left$(strTmp, Len(strTmp) - 1))
            End Select
        Loop While strAllDrives <> ""
    End If
End Sub


Private Sub Form_Load()
    Debug.Print "All available drives: "
    sListAllDrives
End Sub

Private Declare Function GetLogicalDrives Lib "kernel32" () As Long
Dim Drives As Long
Dim i As Long
Dim LasUnidades As String

Private Sub Form_Load()
Drives = GetLogicalDrives
For i = 0 To 25
    If (Drives And 2 ^ i) <> 0 Then
        LasUnidades = LasUnidades + " " + Chr$(65 + i)
    End If
Next i
MsgBox LasUnidades
End
End Sub