Is not a solution to run XP but not connect to the internet?
Well, yes, but given we are talking about people who see it as acceptable to run an ancient version of a browser on a computer that is inevitably connected to the internet, then the likelihood of said XP machine remaining disconnected from the internet for long is somewhat slim.
Neither ancient browsers or obsolete operating systems are the answer... up-to-date CBT combined with correct browser plugins is.