this will keep the HD audio drivers from 197 installed (and test an idea of mine ....)

I'll give it a try with the 197.xx driver series. On a clean windows 7 installation the nvidia hd audio driver was never installed at all and even the device's were deactivated and it still froze randomly (with 258.xx and 260.xx). Like i said above, i tested 3 evga gtx 470's now and all have the same problem (they also have the same bios i don't know if evga has different bios versions for these cards). 
 
Other suggestions i found on the internet:
 
set the ram timings and voltage manually (set voltage higher if all slots are populated)
set the pcie bus frequency manually to 100 mhz
set the northbridge voltage a tad higher
 
Even if all these adjustments help to prevent gtx 400 cards from freezing a user shouldn't have to go through all this.
Fact is any not-nvidia-400 series card does just work. I had no problems for 5 days until this morning when my pc black screened again a minute after windows login. Maybe the cards are sometimes in a bad mood lol its always like that for me, freeze 2-3 times a day, then 4-5 days fine, freeze again, and another 4-5 days fine with no problems. Hardware is either defect or not but this is getting ridiculous. I'm waiting for nvidias response as their technical support guy said he will try to reproduce the problem.

Everything is left at AUTO/Default in the BIOS. The timings look correct as far i can say:

Nvidia's HD Audio Driver did indeed corrupt my Realtek Audio, i had to remove and re-install it. I also had a Creative X-Fi Titanium PCIe card installed and disabled the Realtek Onboard but its the same problem.

Thanks for your help. I will write down all BIOS settings or take a pic when i'm back at home.

agreed.  my 470 has been rock solid stable until 256.

billy, please understand that until drivers are installed,  your graphics card is running as a basic vga device.

thats because theres no acceleration, no acceleration means the gfx card is barely being used.
 
are you able to install 197.75?

Just wanted to let people know that I did not have to disable my hd audio after I installed the new 260 whql driver. It was still disabled from before. So for people asking do you have to repeat the procedure, at least for me answer is no. Of course some may have to repeat it, I just didn't it. Everyones system is different and different results can and will happen.

I ran into an issue with the hd audio. I lost my sound. I went into MoH and could no longer hear sound. Upon existing game, resolution went to 800x600. I restarted system. Manually changed resolution. I enabled hd controller that was related to my video card. It got dectected. I put my headset on and still no sound. So I went into Windows sound and noticed my headset was not the primairy. So I set it back to primairy in playback and recording. It appears I had to enable the controller to let it detect the driver since that was what the system wanted to do. So I assume you have to enable the hd controller before you install a new driver. At least that's what my system wanted to do, otherwise I couldn't get my sound to work. Maybe if I had checked the windows sound first, I could have avoided re-enabling the hd controller but I am not sure. I just let the system do what it wanted then I reset my settings for sound from there. People will likely just have to try and see what works for them.

Hey I had the same problem and none of the suggestions really worked. 30-40 times rebooting just hoping to load windows so I could try another solution. This is what I did to solve the problem I was having with my 460 after trying everything else. Downloaded DLPFix64.zip from the Nvidia forums:
 
http://forums.nvidia.com/index.php?showtopic=88391
 
It is the 4th post down the page.
 
Unzipped the file, ran it and chose disable digital audio over HDMI. It may not have been offered for the same problem I had but I can tell you I now boot into windows every time.
 
I still need to check to see if my sound still work or if I need to install the drivers again. No guarantee but at least I can now boot into my system again. Give it a try if you are like me and nothing else worked. You can always revert.
 

no and i have 2 470 cards, both do it sometimes. one was send in for rma and i got it back cause no problems in the retailers test system (tested for 20 mins). maybe i should buy another motherboard and cpu + ram, i thought nvidia cards would work good with nvidia chipset boards but apparently not. If i get the money ill buy an evga intel board and i7 cpu maybe the cards work then :)

I received a replacment card from EVGA and it hasn't given me any black screens ...... so far.

this proceedure should not cause any type of crash.
please try reinstalling your drivers (clean install 260.99) and the only follow the first part of the proceedure (steps 1-4) to shut down the hd audio device.
if you need further assistance please let me know. 

Sorry to hear it did not work. Truth is maybe one of the 7 other things I tried suddenly decided to work. I am now afraid to reboot unless absolutely necessary. 
 
Starting to have nightmares in my sleep again that I am back in time trying to get something to work on an old 386 systems!   

Someone must have a solution, I paid a lot of money for this and I can't even use it, I may as well put my old 9600gt's in as at least I can play games with them.