running windows xp. My tower model says HP Pavilion 553w. I have looked online to find the specs for an upgrade to memory and processor. It says I have a 478 socket...... Actually I checked the socket manually and I'm running a 462 socket not 478. So I do not trust what that site is telling me. My current processor is a 1.73 Ghz AMD Athlon Socket 462. What is the max I can upgrade to?