"application has been blocked from accessing graphics hardware"

I have a gtx 970 and mines been doing it with fallout 4! all my other games run fine, just fallout 4 cant play atm.

Not that I know of, welcome to the Nightmare.  You'll just have to try the common stuff and cross your fingers its not hardware.  First swap drivers, and increase the TDR Delay in the registry. there are about a handful of things to try from the net. On my system none of them worked, Mine was hardware(memory module) issue with Windows new OS. Windows 7 and up.

I've  deleted, reinstalled and updates drivers.   HP support has deleted, reinstalled and updated the drivers.   Still experiencing the issue.   I'm running Windows 10 on a new laptop.

And here it is March 2016 and I have just found the same freakin problem and I am not about to go through the steps described a few posts up. It is ridiculous that I am facing this after finding out its been a problem for so long. I have done so many things trying to find out what is wrong and $700 paperweight also! Spent extra to get more ram and more space only to find the clouds solve the space problem (a waste of my money getting such large storage), but what good does it do if I keep having problems operating. I am just playing video games (not even sophisticated ones, but simple and its constantly failing. Just now I got the message, previously it went undiagnosed, but getting the message hasn't helped me a bit). Please tell me this is now fixable!!!! PLEASE!!!!

Oh yeah, and I originally purchased windows 8.0 and now have 10pro. What a joke.

Did you try to downgrade your drivers? Try installing the drivers without any control panels like amd's and nvidia's software? Try different video cards ( if only on desktop) try updating all of your drivers, not just graphics, try basic graphics driver? Faulty hardware?