I got my hands on an old Sony Vaio VGN-SZ71XN laptop, and i think it's GPU (Nvidia 8400M GS) is overheating on idle.On boot it's about 55 C, and 10 minutes after or so it stabilizes around 70 C, crashing after a few minutes of Youtube videos. I opened it up, replaced the CPU thermal paste (cpu temps are a lot better now), cleaned the fan with pressured air, but i didnt manage to reveal the GPU heatsink to replace the thermal paste. The CPU can be accesed from the bottom of the laptop, while the GPU seems to be under a small metallic plate under the keyboard, and I can't access it. Any ideas on how to improve GPU temps or if i can access the GPU and replace the thermal paste? Some additional info : This laptop was working great until some months ago, when blue lines started appearing on boot, and eventually it would crash, some times it didn't even get to boot into Windows.That is with Vista, installed from Sony's HDD partition and all the drivers it came with. Later i installed Win 7 and 8.Blue lines and artifacts would appear every now and then but the pc would not crash.The GPU btw showed up as "Standard VGA Graphics adapter" and i couldn't monitor the temperature. Last night I installed Win 8.1 x64, and with some INI file changes managed to install the latest (v337.88) Nvidia driver (without changing the INI file, the error "The Installer Cannot Continue The Graphics Driver Could Not Find Compatible Graphics Hardware Installer" appears). Is it possible that the driver alters the GPUs behavior causing the crash instead of just artifacts?