BSOD and atikmdag.sys

Hello everyone, my first thread here (and hope my last in this section ), but I have some problem that I cant solve myself since I know almost nothing about PCs. I desperatelly need help with some BSODs I have being experiencing since almost when I bought this PC (back at june with vista 32):

Intel Corse2 Quad 9550 @2.83GHz
Gainward ATI Radeon 4870 x2
4GB RAM
Windows 7 64-bit
No overclocking done

Very often during games that by no way my pc should have any problem, at least at the settings I am using, I will get some strange little red squares all over the screen along with some strange sound and then BSOD will appear. When I restart into safe mode everything will be fine, but sometimes when I restart again in normal mode I will get another BSOD. Also, when I used to have vista, the windows told me that "ATI drivers have stopped working properly" even though I had the latest version. Now that I have win7 though, windows will try to find a solution but nothing will come up (like I click on the button "find solution", the loading bar will appear but then nothing). And last thing (finally) is that for some reason CCC wont start and instead the message "CCC: Host Application has stopped working" will appear everytime I start my PC.

So that is pretty much all, I have tried myself many things like various versions of ATI drivers but no luck. Any, and I mean it, help is welcome, and if you need more info on my specs just ask, I will probably spam F5 all the time untill someone answers .

PS about the DMP files, when I open them with debugging tools, the 1rst one is about a ntokrnl.exe (nt+85d3b), while the rest about atikmdag.sys (atikmdag+126a0)

PPS also here is a driver scan DriverAgent.com - THANOS-PC , just in case an important driver is missing.

When you installed Win 7 did you install the mobo drivers recommended by Dell that support Win 7?

Here's latest drivers for your vidcard: ATI Catalyst? Display Driver 7 - 64-Bit Edition

Yes, I installed them some days ago, you can also check DriverAgent.com - THANOS-PC about my drivers.

Thanks for the help Usasma, I will start doing what you suggested and report back the results. One thing for sure is that its not something wrong with the temperature since most often the BSOD comes when starting a program (like a game) and I can even feel that the video cards are almost as cool as they would be when not working by "touching" them. But I suspect that the video cards have been the problem from the beggining. Is there any known issue with them? (I think this one here is what I have Gainward Radeon HD 4870 X2 Golden Sample With a Three Slot Cooler | The Geeks Of 3D - 3D Tech News but I am not very sure since I didnt build this pc, it looks pretty similar though)

Again, thank you very much for the help.

Alright, unistalled old drivers, cleaned with Driver Cleaner Pro, installed new drivers without CCC and then restarted.

And then a new BSOD appeared at the Welcome screen

Here is the minidump file

Ok, just took a look inside the case, there isnt any enormous amount of dust and all fans are working perfectly, but forget what I said about the video cards being cool, I actually touched them this time and they are quite hot. Is there any way that I can check their temperature apart from CCC while running some heavy games? Their high temperature might as well explain why sometimes before an BSOD the screen freezes and small red squares appear all over ?

Small red squares is guaranteed to be either a heat issue or defective card.

Use ATI Tray Tools to set the fan speed to max while playing and also slightly underclock too.

Great, thanks once again, Im loving these forums more and more .

Quick update though, just had another freeze after 10-15 mins of playing Team Fortress 2 on max settings ( no fps drop whatsoever, TF2 is not the heaviest game out there even on max settings and never had a problem running it, but all of the sudden it just froze and had to reset)

Btw I saw on another thread that you suggested removing AVG anti-virus. What else antivirus do you suggest ?

MSE, Avast, Kaspersky should all be good. I've never seen any bsod from them.

I know Usasma uses Avast and I use Kaspersky built into ZoneAlarm Extreme.

Very welcome.