Is there a way that I can return all available local drive letters ? Yes, there is a way !
Declare Function GetLogicalDriveStrings Lib "kernel32" Alias "GetLogicalDriveStringsA" (Byval nBufferLength As Long, Byval lpBuffer As String) As Long
Function GetDrives() As String
Dim tmp As String
Dim iCount As Integer
Dim strDrives As String
strDrives = Space$(64)
Call GetLogicalDriveStrings(Len(strDrives), strDrives)
For iCount = 1 To Len(strDrives) Step 4
tmp = tmp & " " + Mid$(strDrives, iCount, 1)
Next iCount
GetDrives = Trim(tmp)
End Function
Sub Click(Source As Button)
Msgbox getdrives
End Sub