Computer Lock Ups while Creating DVD files/Playing Full Screen Games

[fordianslip]

Hey guys. I'm a complete newb to these forums but I'm fairly technically proficient. Except when it comes to spelling the word proficient of course.

Anyway, around New Years I got the Spy Sherrif virus, and I noticed problems with my computer, aka : Lock ups and freezes. So, after backing up all my files(which were mostly video/music/writing/pictures, so less software than anything), I formated my harddrive and reinstalled Windows XP SP2. I've turned off it's firewall and most of it's security settings and have stopped running Symantec Anti-virus in the background.

Well, when I came back to my computer after installing EVERYTHING again, putting on all programs I had used before my computer had begun "freaking out," I realized I still had the same problem. Everytime I try to play any sort of game in full screen mode, it freezes, whether it's Diablo II or Star Wars Battlefront II. I haven't tried any other games because I'm not a huge gamer, but the game will play fine for anywhere between 10 and 20 minutes before just shutting down my computer.

The same goes for whenever I try to create dvd files to burn to a blank dvd. As a film major, THIS is my major concern, as without the ability to create dvd files, I really have no ability to show my work to people locally.

So I'm thinking it's a hardware issue. My computer is probably three years old? It's a hand me down, but it's pretty decent for what it is. My accessories and stuff however are all pretty decently state of the art, or were last year, so they should still work pretty damn good nowadays.

Operating System : Windows XP SP 2
Processor: Intel Pentium 4 CPU 1.800 Ghz
Ram : 1024 Megs of Ram over two sticks
Video Card 128 ATI All in Wonder Radeon 9600? I'm not sure on the exact number but I'm fairly certain on the Megs of the card and I know it's in the ATI All in Wonder Radeon series
Sound Card : External Audigy 2 NX
USB Hookups(2) : Sound Card(Audigy 2 NX) & External Harddrive[both have always been hooked up]
Two Hard Drives Internal : 40 gig/80 gig.
DVD/CW Rewritable Drive
No USB Floppy

What I just remember is that I used to have a USB Hub, plugged in through a USB Card that is in my PCI slot. Whenever THAT is plugged in, my computer would freeze randomly no matter WHAT I was doing. But since reinstalling windows, I haven't used the hub and I doubt it could be affecting this operating system unless it overfried and burnt out the USB card that's connected to the mother board, and it's slowly wearing the mother board down or something. But I honestly don't have a clue. I just figured that might be something interesting to add to my problems.

As for the motherboard itself? I'm honestly not sure what it is, since well, I can't look inside my case without creating a hassle, and I can't seem to find what it is under my Device Manager in my Control Panel. If you guys want to know this information and know where I can look to find it, I'll be more than happy to supply it.

Also of note, as I reinstalled windows, I went to each website for updates to all of the drivers for anything. I have DirectX9.0c running...

Services in Background? Usually I have Azureus, AIM, Win AMP, and DAEMON, but even with shutting all of these off, I still seem to have the problem I'm describing.

Any help would be greatly appreciated.

Other Notes : I haven't run memtest but I have downloaded it. I just don't have any blank regular cds at this poing to run it, but I will soon, guess I'll post an update if that resolves the issue.

EDIT: I just downloaded speedfan, and it says my temperatures are 40, 68, and -55C somehow. Don't ask me. The Fan spins at 2813 RPM's... so...I've hardly worked with the physics of these electronics, so I'm kinda a dummy on this.