How are you running the script? From an interactive console session? If so, just open up a DOS command window (using cmd) and type 'whoami'. That is who you are running the scripts interactively.
Ok I saw your edits just now...why don't you print the path and check the properties to see if the user account running the scripts has the required privileges?
If whoami does not work on your version of Windows, you may use the environment variables like SET USERNAME and SET DOMAINNAME from your command window.