Crash while playing Games (MW3 MP, Counter Strike: Source, etc.)

K, gonna do this now, did I already mention that sometimes I don't get a dmp file? Like now my latest dmp file is from the 21. july o_o

When I run the driver given on the DELL Site I get this, so I installed the old one again.

No dmp file posted? Are you still getting bsod?

Still thos random pixels/or this random color and nothing reacts and Ican only hardreset! :/

As no recent dmp file has been posted I went through your old dmp files again to see if I could see anything else. The initial bsod was caused by a Direct X file and the first thing you would do to try and fix this is to update the gpu driver and/or update DirectX. The trouble is that you have tried both these remedies without success. DirectX files can become corrupted and as they are so tightly integrated with the operating system that the only real remedy is to re-install the os. I'm going to ask a colleague to go through your dmp file too just in case I've missed something and two heads are always better than one.

Originally Posted by kemical

DirectX files can become corrupted and as they are so tightly integrated with the operating system that the only real remedy is to re-install the os.

I am going to say that I may have to agree with Kemical's suggestion. It bothers me and I know bothers him as well when we are unable to find the actual culprit responsible but sometimes it happens and if and when system files become so corrupt that the system is unable to run reliably sometimes there is little to no other recourse.
I read this thread as well as your thread on the other forum a couple times. It is not however, clear that when your system hangs (with or without a Blue Screen) which monitor experiences the color / pixel distortions or if it is both. Normally I would associate this with a video driver problem or corruption somewhere in the subsystem and recommend troubleshooting DirectX Diagnosing basic problems with DirectX but I suspect you are well past that.
It is also not clear whether or not your system exhibits these same symptoms without the external monitor connected.

You have one suspicious driver
X6va009 6/8/2012 I say suspicious because I can find anything regarding it in my normal driver reference databases and when I Google or Bing it, it doesn't look too good.

You have one very old driver
Kone.sys 12/11/2008 ROCCAT Kone Gaming Mouse ROCCAT STUDIOS V3.0 - SUPPORT » Support - Mice » ROCCAT Kone this is way too old and since your issues seem to involve gaming I would suggest either update, upgrade, uninstall, remove device and rename driver to break it to Kone.OLD

Update your network adapter drivers
Rt64win7.sys 6/10/2011 from here Realtek
and
NETwNs64.sys 10/31/2011 Intel Wifi from here http://downloadcenter.intel.com/Deta...20Applications

While you are at it update your audio driver
RTKVHD64.sys 2/18/2011 from here Realtek

Finally and I am not sure this will actually address any underlying problem and I don't know how you are interfacing your external monitor with your laptop, but I would strongly recommend if you are using the HDMI interface port, that you use the best cable you can afford. Shielding is very import in HDMI cables and a poorly shielded cable can result in any number of problems. One of the reasons I was wondering if you ever experience the problem when the external monitor is not part of the equation.

Today I experienced something really nice.
I booted my Laptop without the external Desktop and my Laptop and my MW3 resolutions were both 800x600 and I was able to play for like hours.
And by the way I already reinstalled my OS like a month ago, hopped that this would fix it. :/

ButI still would like to be able to plaz on mz big desk /-.-

Can you advise if there is a physical switch or other means to isolate your dedicated video card and disable your integrated video card so you are actually only using the nVidia and taking the Intel out of the equation? You probably don't want to have both of them enabled simultaneously.

As far as I've been able to ascertain this laptop uses the Intel graphics for every day use but when something more intensive like games is used then the NVidia card kicks in. According to what I've read you can change the settings so it only uses the Nvidia card as Randy suggests. Open up the graphic options by clicking the icon in the bottom right hand corner. See this:

xps 15 L502x Video card confusion (intel and gt540M)