Well, fixit, I had DL'd CPUID Hardware Monitor, which I saw was recomended in another CPU overheat threat, which showed that my idling CPU temp was about 30 upon startup, but slowly climbed the longer I used it. The temp got to ~60 max in each core (while DL'ing some games off Steam) before I turned off my PC.

I waited a few hours (TV) and now that I'm back on CPUID is still giving me temps of 36-40 Celsius, and a max of 48 C.

I took your advice, fixit, and tried SpeedFan, but it's giving me temps of 18-20 Celsius, which seems waaayyyy to low for this to be real. I don't think that's a typical temperature outside of water-cooled systems, is it?

I'm ashamed to say I used a no-name Chinese-labeled heat paste when I re-did my paste, because I'm living in Singapore, and it was recommended by the shop.

On another note, I know the CPU has no dust in between it and the heatsink, and that the fan is on tight and steady.

Edit: I just now started DL'ing the Left 4 Dead 2 Demo, and my CPU usage kicked up to 40% on both SpeedFan and the desktop gadget. However, CPUID tells me my temps are about in the 45-50 Celsius range, while SpeedFan is insisting on 25-30 Celsius. Should SpeedFan be calibrated, or something?

hi that temperature is not unknown either could you try this temp program CPU Thermometer free download. CPU Thermometer is a free CPU temperature monitor, it can show your pc CPU current temperature in desktop and tray icons zone, the temperature be live... and see if it matches either speedfan or the cpuid reported temps ,
ive just tried it myself and it matches exactly my readings from speed fan ,
callibration is not usually needed as it takes the readings from the system chips ,just check that it is reporting the correct system details
please post the temps from cpu thermometer

OK, I just stuck in my second RAM stick, and while on Facebook, it shut off. I'm going to try the Memtest86.com - Memory Diagnostic here, and see if that can tell what is going on. I had it on for two + hours, and it stayed on, but when I turn off, and stick in my second RAM, it shuts off. Thinking it may be the RAM.

Also, my case is open on the side, and I have a mini-USB fan blowing into my case, which seems to drop my CPU temp by 4-5C. Should I invest in an auxiliary fan?

if your system was running fine before putting the other ram stick in ,and then it crashed after putting it in then it would be acceptable to think there is an issue with that ram stick, are the ram sticks identical ?
certainly run memtest 86 , but i think that you said before you had issues trying to install win7 , and in post 6 you say "My dad insisted on re-installing Windows 7 after I formated the drive, and only worked when the side of the case was off, and he took out one stick of RAM" this again would seem to point to a bad ram or incompatible ram stick

what did the cpu temp program report as the temps ? was it similar to speedfan or cpuid ?

I'm actually not getting anything from CPU Thermometer at all, while SpeedFan is still saying 20-26 C and CPUID is showing ~40 C while idling.

I'm not sure if CPU Thermometer is the right program for my processor, it says that I'm using a Intel i5 750 (correct) which has eight active cores (?). It's giving me a frequency of 121.2 Mhz * 22 = 2666.9 MHz, which doesn't make any sense to me.
Is there a patch / update I need for this to work with Windows 7 (I went to CPU Temperature Monitor but it doesn't say anything about that)

do you have a hardware monitor in built to the bios ?, could you check the temps in there?

before buying extra cooling fans or reseating the cpu with different thermal compound , we need to find out the correct temps of the system first ,speedfan is recommended by alot of the techs here and the max temps given so far are not untoward , another temp program you could try is Motherboard Monitor - Free software downloads and software reviews - CNET Download.com it doesnt support all motherboards ,but check your board and see if its compatible

That was from my BIOS hardware monitoring, which is why I am leaning towards believing CPUID Hardware Monitor.

On MemTest, whenever I tried to use version 3.5, it would turn off in the first 30 seconds, as before, and the same thing when I try the "experimental" version 3.5. However, using test version 3.4, it passes the test with no errors or problems.