My Dell Inspiron 1525 (Vista Home Premium, Core 2 Duo processor, 4 GB RAM) has started to just shut down right in the middle of using it. No BSOD, just a completely turned off machine. I think it is getting too hot as this happened a few months back at which point I took the cover off of the back and cleaned a bunch on lint off of the thing that disipates the heat. That seemed to work. i also installed SpeedFan and it measures temps up to around 55. I don't know what the temp is when it shuts down. I tried opening and cleaning that piece again but it was not dirty this time and I am getting lot's of shut downs. Typically it is when I am running on the battery only. Is there another compartment to open up that has another one of those heat sinks to clean? It seems to feel hottest in the front left of the keyboard and I don't know what if anything is under there (or how to open any other compartment to check). After the sudden shutdown I have to reset the day and time.