Hi, First post. Be gentle! I have found lots of posts about computers freezing up (no activity other than a movable, but ineffective, mouse pointer), but none with my specific set of circumstances. o My PC boots fine o WinXP (SP3) starts without issue o All apps open as expected, as long as opened in the first couple of minutes after start up o Within 3-5 minutes of Windows start-up, regardless of level of hard drive (in)activity, system freezes -- mouse pointer only; no other control possible; must either hit reset button, or hold in power button for several seconds to shut down PC. When I reboot, the same sequence of things happens. Last week I discovered, much to my embarrassment, some major dust collections, which had blocked signficant air flow into the case. I cleaned all vents, which reduced onboard temp readings (down from mid 40's to upper 30's -- low 40's Centigrade; I knew onboard fans were revved up, but never did anything to investigate). Now all temp readings are in upper 30's to low 40's (Centigrade), EXCEPT the SMBus, which is still in the mid 120's! (it dropped 2 whole degrees after I cleared the vents) Questions: How could the SMBus readings be SO much higher than all the others? Could those high temps have damaged my RAM sticks, making them unstable, so that now they last only 3-5 minutes before freezing? Is there any way to verify the exact cause of these freeze-ups? Thanks, Bill Coley