Option Explicit
'On Error Resume Next

Dim WshShell, WshFileSystem
Dim objFolder
Dim strMyDocuments
Dim floatSizeFolder, GygaByteSizeFolder

set WshShell = WScript.CreateObject("WScript.Shell")
strMyDocuments = WshShell.SpecialFolders("MyDocuments")
  
Set WshFileSystem = WScript.CreateObject("Scripting.FileSystemObject") 
Set objFolder = WshFileSystem.GetFolder(strMyDocuments)

WScript.Echo strMyDocuments
WScript.Echo objFolder.Size

floatSizeFolder = (objFolder.Size/ 1024 )/ 1024 / 1024 

GygaByteSizeFolder = FormatNumber(floatSizeFolder,  3 , , ,  0 )

WScript.Echo strMyDocuments & " size is " &  GygaByteSizeFolder & "Gb."