Hey, I installed Windows 7 on my Dell Insprion 6000 laptop. Windows was running slow b/c I still had the standard 512MB of RAM vs 1GB the system requires. So I bought a stick of 1GB DDR2 PC2-6400 and installed. (After doing some research I found that I should've bought PC2-4200, but should be okay, right?) I now have 256MB in one bay and the 1GB in the other. Upon starting my computer, I receive a message that new hardware has been found, and then windows begins. The problem is that Windows just "hangs up" and the screen continues to say "loading windows..." and nothing else happens. Any thoughts on why I can't get this to work?