Microsoft VBScript runtime error: Path not found - vbscript

Question

I want to execute a vbs script which provides me the size of a given folder but at the execution it returns me the error:
Microsoft VBScript runtime error: Path not found
Previously, the error was
Microsoft VBScript runtime error: Permission denied
but after these commands:
takeown /f C:\Users /r /d y
icacls C:\Users /grant administrators:F /T
it turned into "path not found". As you can see the folder that I want the size is C:\Users.
Here's my code:
'Created the 18.03.2010
'Easy script for check space folder. You need NRPE_NT daemon on win computer
'##########################################################'
'Install'
'##########################################################'
'1.copy file to c:\ for example... c:\nrpe_nt\bin\check_folder_size.vbs'
'2.set your nrpe.cfg for command for example
'command[check_foldersize]=c:\windows\system32\cscript.exe //NoLogo //T:30 c:\nrpe_nt\bin\check_folder_size.vbs c:\yourfolder 50 78
'50 70 are parameters for warning and critical value in MB'
'3.restart your nrpe_nt daemon in command prompt example.. net stop nrpe_nt and net start nrpe_nt'
'4. try from linux example.: ./check_nrpe -H yourcomputer -c check_foldersize and result can be OK:22,8 MB'
'it is all'
'##########################################################'
Dim strfolder
Dim intwarning
Dim intcritic
Dim wsh
Dim intvelkost
Dim intjednotka
'##########################################################'
Set objFSO = CreateObject("Scripting.FileSystemObject")
Set wsh = CreateObject("WScript.Shell")
'##########################################################'
If WScript.Arguments.Count = 3 Then
strfolder = WScript.Arguments(0)
intwarning = WScript.Arguments(1)
intcritic = WScript.Arguments(2)
Set objFolder = objFSO.GetFolder(strfolder)
intjednotka = 1048576 '1MB->bytes'
intvelkost = objFolder.Size/intjednotka
If (objFolder.Size/1048576) > CInt(intwarning) Then
WScript.Echo "WARNING:" & round (objFolder.Size / 1048576,1) & " MB"
WScript.Quit(1)
ElseIf (objFolder.Size/1024000) > CInt(intcritic) Then
WScript.Echo "CRITICAL:" & Round(objFolder.Size / 1048576,1) & " MB"
WScript.Quit(2)
Else
WScript.Echo "OK:" & Round(objFolder.Size /1048576,1) & " MB"
WScript.Quit(0)
End If
Else
WScript.Echo "UNKNOWN:"& strfolder &"-" & intwarning & "-" & intcritic
WScript.Quit(3)
End If
The line of the call of the script:
check_foldersize = cscript.exe //nologo //T:60 scripts\check_folder_size.vbs C:\Users 4000 5000
Edit: One more useful point : There are no errors when I change the folder C:\Users to C:\Intel for example. So it seems to be a problem linked to the Users folder itself. Then I don't think that iis_iusrs permissions are the cause.