Error Update Windows XP SP2

[ktx]

I using Windows XP Professional , when I update Windows XP SP2 :

My computer appear error :

The System cannot log you on. Make sure your Username and domain are corrct, then type your password again . Letters in password must be typed using the correct case .

And Error :

The System cannot log you on due to the following error : 
The parameter is incorrect. Please try again consult your system administrator

I in Safe Mod , type username and passeord administrator but it isn't login my computer . Please help me .