As I recall, you're the one who post a thread a few days ago about the same issue. Have you done a clean install of the XP by reformatting the HDD as I suggested?
As for the overheating issue, how much fan do you have in you PC case? The ambient temperature also determine the CPU temperature rise. The cooler the case temperature, the cooler the CPU. Why do you use the old CPU cooler? Don't the Core2 comes with its own?
You're also still having that "freeze at shutdown issue". With a clean install, that shouldn't have happened. Unless the cause is not the OS.
Lastly, what's the brand of your PSU? Since it might have something to do with your current issue. Take note of every possibility won't hurt.
UPDATE: Just flashed my BIOS, after re-installing windows, my BIOS actually let me flash it and no longer has the PC WONT TURN OFF problem!
So just for reference, BIOS did need flashing to next version, and a windows re-install was necessary, also my original stock CPU cooler was broken as one of the legs had a missing 'plastic clamp prong' and now I have a new cooler which is brand new and has fixed the overheating problem!
PC Fixed all thanks to you guys! Thank you sooooo much
I already have 2GB of RAM and would like to up this to 4GB of RAM by adding another 2GB stick. I've been advised to always install memory in matching pairs, but do I need to have the same brand of RAM as what's already in my machine (Ie mix my Rendition RAM with lets say Crucial RAM).....