Running Win7 x64. Had my PC running for about 12 hours now with various relatively lightweight apps (Word, Thunderbird, Firefox, etc.) I have 4 GB of RAM in my system. Resource Monitor reports that 514 MB is hardware reserved (512 MB of it for my IGP), 2,100 MB is on Standby, and only 142 MB is truly free. I've frequently seen it dip to just a few megabytes free. But never have I noticed the computer slow down as a result. It can always grab some of the cached data in the Standby RAM if it has to. I'm eagerly awaiting the response from MS, which I'm expecting will vindicate Win7.