System Freeze - Can anyone assist me?

Sup peeps...I just started getting a system lock-up. I'm not sure if this is the right place to post this but I figured here would be as good a place as any. Wondering if anyone had any ideas...this is what happens...

I start my system. Go to launch any game like F.E.A.R, CS etc. After a few minutes my whole system is locked up.

Video Card: GeForce 6600 265MB 8X AGP
Drivers: Forceware Version 94.24
Monitors: NEC Multisync FE950 & Viewsonic VG2021m
OS: XP Pro
DX: 9.0c

I just started having this issue in a past week. Tried most everything to see what's up. Could it be the Video Card overheating? Monitors going bad? I set the primary monitor to each one and also tried it with just 1 monitor plugged in as well with the same results. Basically what happens is after a few minutes while I'm in-game the screen(s) lock up and I have to manually reboot my system. Any help would be greatly appreciated!

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System Information
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Operati ng System: Windows XP Professional
Processor: AMD Athlon(tm) XP 2500+, ~1.9GHz
Memory: 1024MB RAM
DirectX Version: DirectX 9.0c

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Display Devices
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Card name: NVIDIA GeForce 6600
Chip type: GeForce 6600
Display Memory: 256.0 MB
Driver Version: 6.14.0010.9424 (English)

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Sound Devices
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Description: SB Audigy 2 ZS Audio

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Devices
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Devi ce Name: Razer Diamondback Mouse
Device Name: Logitech HID-Compliant Keyboard
Device Name: Nostromo n52 Speedpad2

I know a lot of my stuff is old but I've been running those games listed and more since they have been released. The psu is 500w and doesn't have a problem. This is why I'm posting here!

This issue "just" started last week after I upgraded my nvidia drivers from 93.71 to 94.24. I unistalled the old drivers prior to installing the new drivers so that's not a question. I've also tried to revert back to the old drivers and that doesn't work now (yes, uninstalled and installed drivers). The case has a few dust balls but no major layers of dust covering everything.