Random GSODs using browser and standard applications, no gaming

My aging desktop has been plagued for a few months with grey screens of death. They started around the same time I bought and installed a Radeon R9 270X and began using dual-monitors. There have been a few BSODs intermingled over the months, but mostly GSODs where the computer stops responding and all I can do is hard power it down or reset it. When audio is playing, the audio continues, but the keyboard, mouse, etc. are all unresponsive.

In March 2015, the BSODs got so bad, as you can see in the picture titled "Errors got bad_No idea what this is_Reinstalled Windows", that I had to reinstall Win7. I updated the firmware on my Crucial SSD that hadn't been updated in years, and hoped that would solve the problem. Since reinstalling Windows in March, I've only had 1 BSOD, and that was due to one of my original RAM sticks going bad. There's a MemTest picture of that and also the BSOD right before I ran MemTest.

Since March, I've had at least 7 GSODs, and I feel like I've tried everything under the sun except buying a new GPU. These GSODs do not create any dump files or any events that I can find. You can see attached pictures (with somewhat descriptive titles if you hover the mouse over them) for each of these tests:

• I've installed new memory, and you can see 12GB passed MemTest through 7 passes.
• SFC Scannow shows no integrity violations
• IntelBurnTest passes on Standard, CPU gets a little warm for my liking on High/Very High
• SeaTools Short DST Passes
• Driver Verifier ran for 24 hours with no crashes
• GPU-Z Stress test with Unigine Heaven
• GPU previously tested with Furmark, no issues

I've uninstalled all AMD drivers, booted into safe mode, ran Display Driver Uninstaller to remove any remaining drivers, and deleted all instances of ATI/AMD folders in the file system and registry. Then I reinstalled the drivers.

I tested the system for days with just a single monitor hooked up, and I once again got a GSOD, this one was on April 30th. At the time, the monitor was hooked up with HDMI. I've had my monitors plugged into DVI-I, DVI-D, and HDMI and it doesn't seem to stop or change the GSODs.

When I ran Unigine Heaven, I manually set my GPU fan speed to 100%, because Catalyst Control Center just showed it sitting at 20% even as my GPU temp got up to around 65C. I've heard that some card fans don't kick in until 70C, but there's still the possibility that there's something wrong with the automatic settings of my case, internal, or GPU fans, and therefore there's a heat problem. But I have also had logs of GPU temps all the way up to a GSOD and didn't notice any spikes.

I use Chrome as my standard browser and have recently tried turning off GPU hardware acceleration, not sure if that could be the issue. I've got Norton Security installed as well. MalwareBytes and Spybot have been run and it doesn't appear to be malware or spyware.

The computer normally goes for 2-7 days running just fine and then I get a GSOD. I'm at a loss for what to try next. I'd like to avoid buying a new GPU if I'm not sure that's the problem, but having a consistently unstable system is really bugging me. Any help would be very appreciated. Thanks.

Code:

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*                        Bugcheck Analysis                                    *
*                                                                             *
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Use !analyze -v to get detailed debugging information.
BugCheck A, {fffff980000000e2, 2, 0, fffff80002fb8b74}
*** WARNING: Unable to verify timestamp for cewd64f.sys
*** ERROR: Module load completed but symbols could not be loaded for cewd64f.sys
Probably caused by : cewd64f.sys ( cewd64f+3d1e )
Followup: MachineOwner
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You only had 2 dump files, one showed an inconclusive analysis, the other blames cewd64f.sys which I can't find any conclusive information on (could be malware).