BSOD while playing Space Marine, LoL, Etc.

Hello, here is the information requested.

- Model: Studio XPS 8000
- Manufacturer: Dell
- Windows 7 Home Premium - 64bit
- Full Retail
- Age: 1.5-2 years old (?)
- Same as above, i have not re-installed
- 4.00 GB Ram
- Intel(R) Core(TM) i5 CPU
- NVIDIA GT 220 (Driver version 280.26) (Graphics clock: 615 MHz, Processor clock: 1335 MHz, Memory clock: 790 MHz(1580 MHz data rate)


When playing Warhammer 40k: Space Marine, (I can play for about 5-10 minutes) or League of Legends, my screen goes black, then all audio is lost, and my computer turns off, and comes back on. I can get on the internet and go to websites like this and whatnot, just seems i can't play games.

I hope I posted what is asked, if not let me know.
Thanks,
Joey

Whoops, didn't add this.

Problem signature:
Problem Event Name: BlueScreen
OS Version: 6.1.7601.2.1.0.768.3
Locale ID: 1033

Additional information about the problem:
BCCode: 116
BCP1: FFFFFA800A5064E0
BCP2: FFFFF8800F814FA4
BCP3: FFFFFFFFC000009A
BCP4: 0000000000000004
OS Version: 6_1_7601
Service Pack: 1_0
Product: 768_1

Files that help describe the problem:
C:\Windows\Minidump\091211-16941-01.dmp
C:\Users\Joe\AppData\Local\Temp\WER-56269-0.sysdata.xml


I've also found these errors in my Event Viewer's Logs.

Critical: 9/12/2011 6:41:32 PM Kernel-Power "The system has rebooted without cleanly shutting down first. This error could be caused if the system stopped responding, crashed, or lost power unexpectedly."

Error: 9/12/2011 6:41:51 PM BugCheck "The computer has rebooted from a bugcheck. The bugcheck was: 0x00000116 (0xfffffa800a21c4e0, 0xfffff8800fabafa4, 0xffffffffc000009a, 0x0000000000000004). A dump was saved in: C:\Windows\MEMORY.DMP. Report Id: 091211-17362-01."

I've also found these.

Error: 9/12/2011 5:01:37 PM Service Control Manager "The following boot-start or system-start driver(s) failed to load: RxFilter"

Error: 9/12/2011 5:01:04 PM Service Control Manager "The SessionLauncher service failed to start due to the following error: The system cannot find the file specified."

Thanks,
Joey

I just played Space Marine for about 30 minutes, and Dawn of War II for about an hour, and nothing happened. No restart, no shutdown, no bluescreen. I'm really confused as to what is/was wrong, and why this problem happened so frequently earlier today.

Any* suggestions for me to look into in-case something just didn't trigger it when i was playing just now?

Thanks,
Joey