I recently installed the 32bit Vista Ultimate on my own built ASUS P5K deluxe wifi board with 4GB DDR2 memory. A few days after the initial install Microsoft allowed me to install SP1. This was about 10 days ago. Immediately after the SP1 install I noticed that Vista recognized the total 4GB Ram, and before it would not. Microsoft tells me that SP1 not only recognizes 4GB memory, but it now has the capability to use up to 4GB memory. Is this true, or did I misunderstand Microsoft?