Hi,
I also suffered under this random crash to desktop every 15min (or so) and non of the suggested solutions helped me.
But....
Finally I solved it, at least on my machine. The problem on my machine were the onboard realtek HD audio and the Nvidia Audio (which is included in the nvidia driver). I disabled the nvidia audio (and updated the realtek driver simply to be sure) and no further crashes for 4 hours now.
I hope I could help someone with this.
My System:
Mainboard gigybyte Z77-DS3H
Windows7 x64
GTX 670 OC