|On 16/11/2009 at 15:43:39: [[ Relative TechSupport, how can I confuse you? ]]|
Tactically, its worth using a version of windows that's at least one major release *behind* that of your "customer".
Then you're entirely accurate in saying "Vista? I'm sorry, I've never used it. Have you tried ringing the people you bought the machine from?"
Windows 2000 FTW.