I downloaded something named CPUID Hardware Monitor, only I'm somewhat thrown by all of the various voltage numbers for the motherboard, the graphics card, and the power usage of the computer as a whole. Also, the idle temperature of the graphics card is holding at ~50 degress celsius, usually 51-53 until late evening when it seems to go to around 47 (at least it did yesterday).
Here's my set-up:
ASUSTeK Computer INC. M4A78LT-M-LE
AMD Athlon II X4 640
Nvidia GeForce GT 240
Memory 4.00GB
Microsoft Windows 7 Ultimate 64-bit 7601 Multiprocessor Free Service Pack 1
So, what should I be looking for when testing Skyrim and other games that have acted up? I know that the card has a maximum of 105 celsius, so I shouldn't be too worried if it goes to 70-80 celsius (right?

Since the system becomes unstable after a BSOD event, causing a cascade of them and forcing me to shut the computer down completely for a short while, I'll probably have more than one chance at seeing what happens prior to a BSOD, and to see how one happening after a reboot from a BSOD goes down. I didn't do this before, and it probably would have saved some trouble (replaced the harddrive because that failed all of the manufacturer tests...unfortunately, it appears it wasn't responsible for my BSOD errors, but at least it isn't a potential factor any longer).
I wish the problems had not magically started up again, and they haven't happened for 3 weeks (haven't touched a single game in that time). Unfortunately, they always started outside of a game first, then migrated into Skyrim at a later date, and were consistent. Empire actually froze the entire system, and there was a BSOD upon booting into safe mode (it loaded the driver list, then kaputnik!). The errors all seem to point towards hardware or drivers; I did update to the latest Nvidia drivers (18th Feb) 3 weeks ago, but haven't put them to the test to see if that fixed the problem. Really want to figure this out, because I work extensively in Photoshop with very large textures, and hope to get back into using Maya - don't want any related BSOD events sneaking up behind me!