I am Microsoftie 4 ever (19+ years) working in Windows Services and Content team in the UK, my blog is mainly focused on the Windows family of products and trying to provide help pointers and resources for customers on our products.
I just wanted to highlight this great article we have about 64-bit Windows.
Taking the mystery out of 64-bit Windows
It covers a whole bunch of topics such as:
For more information, see 32-bit and 64-bit Windows: frequently asked questions.