I started getting the atikmdag.sys bluescreens as well, but it looks like it's related to something with MSI afterburner.
Any time I tweaked any of the clock speeds from the default clock it'd crash. Disable the Unofficial overclocking EULA flags in the config file might have done it as well.
Maybe it's a conflict between catalyst control center and MSI, but regardless, that seemed to help me.
I thought that too. When I first started mining, I ran my GPU at stock - I was too scared too overclock. Then I took the leap and used MSI afterburner - got my first blue screen (the one posted in this thread) It then happened a few more times. Couldn't afford the downtime so I uninstalled MSi afterburner and went back to stock and all was fine. I now use Sapphire TRIXX to overclock and its actually been fine, but one day last week i did get a BSOD.
To me its not fixed - well in the sense that even though its been fine for days, it did happen once with the current setup, so I'm inclined to believe that its still lurking around - I just haven't done anything to the system to make it crash yet, but I'm sure its only a matter of time.
I personally feel that MSI afterburner did something thats messed things up. Would like to know if anybody is getting BSOD with the "atikmdag.sys" file error and they have NEVER installed MSI afterburner?
I've read some guides on how to replace the "atikmdag.sys" in windows system with a different version from the drivers exe. I'm wondering whether replacing the current (and broken) sys file with say either an older versions in 10.4/10.5 might fix the problem?