I'm really not sure what a "rivatuner" is. I think my first two BCCodes were 1b or something to that effect with all 0's for the BCP1-4. I'm not sure if this additional information helps or not.
As far as I know, I have not added any software or changed any drivers
since starting from a fresh install with fresh hard drives three weeks ago. I did make two hardware chages after the new install. I added a second GPU for SLI about two weeks ago. Then I changed my memory from 16GB of Kingston DDR3-1600 to 16GB of G.Skill DDR3-2133 last week. I did play with the auto OC'ing settings of the CPU using my BIOS's pre-programmed settings. But I only had it OC'd for about 30 minutes, then I put it back to default. That was two days ago.
I should add that the first crash happened while playing Starcraft II. I also had several Internet Explorer windows open, Outlook, OneNote, and my WM 6.5 phone was connected with a USB cable. The second crash I was just browsing the Internet. The third crash while playing Starcraft II again. BTW the other programs like Outlook and so on I always have open. Ever since I added my second GPU for SLI I do get random screen blinks.