import ctypes
class disable_file_system_redirection:
    _disable = ctypes.windll.kernel32.Wow64DisableWow64FsRedirection
    _revert = ctypes.windll.kernel32.Wow64RevertWow64FsRedirection
    def __enter__(self):
        self.old_value = ctypes.c_long()
        self.success = self._disable(ctypes.byref(self.old_value))
    def __exit__(self, type, value, traceback):
        if self.success:
            self._revert(self.old_value)
with disable_file_system_redirection(): 
    def IsUserActive(uName):
        import os
        proObj = os.popen('net user')
        activeUsers = proObj.read()
        return uName in activeUsers

    passUserNameHere='MSD'
    if IsUserActive(passUserNameHere):
        print 'Success: '+passUserNameHere+' is active'
    else:
        print 'Fail: No User-'+passUserNameHere+' active!'