Problems with Windows 7 x64 BSOD ERROR

Hi,

I'm having some serious problems with my Windows 7 x64 Enterprise edition. I keep getting 2 separate blue screen of death errors. I thought it was the computer overheating, I took apart the whole computer and did a full dust clean and it greatly reduced my CPU temps and core temps, etc etc. I am running speedfan and my temps are normal after the clean, they were pretty high before the dust clean. I also ran a windows memory diagnostic but that came back no problems. Anyone have any suggestions? I'm using a program called Device Doctor to update my PC drivers, so they should all be up to date. I have NOT updated my BIOS for my motherboard. My PC Specs are as follows: Intel Q 6600 running stock at 2.4 Ghz. Stock CPU Cooler, 9800 GTX running at stock, 4 GB RAM 5-5-5-18 Corsair 2x2 sticks. Everything it running at default settings and have never overclocked anything in the pc. I'm running bios version 1302 in my motherboard, there are newer bios available, but figured I'd ask for help and see if anyone had any ideas before I tried to do that. I heard that is a last resort type of thing to do. Please --- any input will be greatly appreciated. My BSOD errors are ---

Problem signature:
Problem Event Name: BlueScreen
OS Version: 6.1.7600.2.0.0.256.4
Locale ID: 1033

Additional information about the problem:
BCCode: c4
BCP1: 0000000000000091
BCP2: 0000000000000002
BCP3: FFFFF80002E46C40
BCP4: 0000000000000000
OS Version: 6_1_7600
Service Pack: 0_0
Product: 256_1





AND ---

Problem signature:
Problem Event Name: BlueScreen
OS Version: 6.1.7600.2.0.0.256.4
Locale ID: 1033

Additional information about the problem:
BCCode: 7f
BCP1: 0000000000000008
BCP2: 0000000080050031
BCP3: 00000000000006F8
BCP4: FFFFF80002C56E58
OS Version: 6_1_7600
Service Pack: 0_0
Product: 256_1