Actually I have heard of Windows 7 to install on 512MB, but it really really really recommends at least 1GB for 32-Bit.
I almost gasped for air when I saw that screen shot.
Usually OS shuts down as well when the Processor gets too hot so it will shut down as a safety precaution. Might be a dirty fan, needs new heatsink, paste.. whatever.
Also, your ram might be going too.. but usually it doesn't shut down, windows will just crash. *lol*