Hey Kleetus and Ebon-Hawk it is not a over heat problem I am playing Crysis 2 ultra settings with DX 11 turned on and high resolution textures pack installed and I have been playing for a few hours with no problems so far my graphics card sits at around 77 degrees Celsius it doesn't seem like it wants to go higher so it looks good I am monitoring it with GPU-Z.

Have you tried downscaling / switching off features of TW2 engine to see if it makes a difference. It is possible that a specific engine feature is causing a problem....

Are you over-clocking?

No I don't overclock or plan to I am a noob when it comes to computers I don't even know how to put a graphics card in! So I just bought all the latest parts and got my friend to do it I will try turning a few things off in the witcher 2 settings like SSAO or whatever it is and see if that helps a bit but keep feeding me with more ideas/suggestions as I love reading them and again thank you all so much for your assistance it means a lot :)

Might be PSU problem. I have similar experience before, my PC completely shutdown after playing about 2 hours while other games doesn't have any problem. The problem solved when i change my PSU to slightly better one.. (390w to 460w).

I just bought a bran new 850W Corsair 3 days ago and Corsair never have any problems and they have 7 year warranty

Yes, thanks for reminding me about this...

Some time ago I remember a video game that was crashing because the video card have not had sufficient power, yet all other apps were running fine... Based on that I would suggest you check all the power delivery cords to the card, I have not used ATI for a while so I do not know what they have in them these days.

It might be worth noting that I have played Witcher 2 on Windows 7 x64, i7, nVidia 570 for 40+ hours and never experienced an in game crash, so my experience has been very good (though I recognize that this may be different for others).

Seems like the shutdown is only happening when I play The Witcher 2 weird I owned crysis 2 ultra settings dx 11 on high resolutions pack for a good 4 hours and no problems so I hope they patch the game or something.

Checking up for latest drivers and updating it for all components in the system will be better before trouble shooting any problems.

1. Motherboard drivers
2. Graphics card drivers
3. Sound card drivers (<- check this especially)
4. Keyboard and Mouse drivers (if you are using non-standard devices)

Also try the game by switching off the 2nd monitor.

@OP, do you get a moment of any BLUE screen..before system restarts..like for an instant!.

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@OP, there is a 'Power Tune' (Power Control) setting under "ATI Overdrive" tab in the Catalyst Control Center.. Move the slider to -20% and check if that solves the auto_reboot_restart scenario.

If that solves the problem, then you can narrow down the issue to 2:-

1. Graphics card issue
2. Power Supply issue

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http://au.gamespot.com/forums/topic/28665444/the-witcher-2-crashingrestarting-pc

It is happening with a lot of people so it has to be the game itself please look at that link thank you :)

I even read through the inter-links to other locations mentioned on that page.

Wierd...Facts.

1. Majority of them have Intel CPU's (against one who reported using a mid range AMD CPU)
2. Majority have Nvidia cards (except a few), someone mentioned it could be drivers problem
3. A few reported either using HDMI
4. A few hinted using multi displays (my guess)
5. Someone mentioned disabling power saving settings for Hard Disk solved it (but not all)
6. A possible fix, already mentioned..but its related to fixing Game crash not complete system restarts
http://forums.steampowered.com/forums/showpost.php?p=24262368&amp;postcount=100

My guess is the stress on Video RAM....or some component which does report the issue to the OS and get logged. Windows OS will not just restart PC just because of some heavy load in Directx API or some other stuff_there is no such call from DirectX API over OS control set, even if it does it will show a blue screen showing the error code and log it in the event logger (check both application and system logs).

(damn I wish I had hands on a system which has this auto_shutdown issue;) ..damn I just wish I had.... I like trouble shooting stuff)

-Edit-

My self, I never ever* encountered any OS system auto_shutdowns..ever*..

@Op_Zazally, did you check the auto_shotdown issue by adjusting -20% power tune from Catalyst Control!

Also download an app called DXtory..
1. launch the game
2. close the game
3. A game (executable) will be detected by DXtory, select it
4. Browser across all the options in DXtory until you find something called frame rate limiter
5. Enable it and set the frame rate limiter to like 47 (its a long story_wall of text spam_so don't ask why set it at 47)
6. Play the game
7. Check if the issue happens..
8. If that same issue happens, next time run the game with Dxtory 47 frame limit and -20% power tune from Catalyst Control Center.

The above is to specifically check if the issue happens due to graphics load, if not then its the next set of components..HDD (I greatly suspect this, because the HDD starts seeking immediately when you start doing anything in the game apart from being idle. A part of the Page_Table and the virtual memory itself is stored in Pagefiles which is on HDD)

And then System RAM....and sound hardware...

Hello there is NOTHING wrong with my hardware every single part in my computer has been tested and they give positive results I have even played a game which is more graphical intense then the WItcher 2. Crysis 2 my graphics card gets close to 80 degrees Celsius and The Witcher 2 only gets to 67 Degrees Celsius I have no problems with Crysis 2 but with The Witcher 2 I do.

Lol.. alright, suite yourself. You obviously know a lot of stuff and don't appear to require any help as you have nothing-wrong-with-your-hardware, best of luck figuring out why it happens.

-Edit-

Just thought I should mention, the game runs perfectly fine on my system.. :P

Well A LOT of other people are having this problem though and no one has solved it yet so what makes you think you can solve it if you can then you will have millions of people bow down to you sorry if I sounded rude but this is THE ONLY game that is having problems if I had hardware problems I wouldn't be playing Crysis 2 at maximum settings cause Crysis 2 requires a much better computer then The Witcher 2 does.
Also I appreciate the time and effort you spent in writing that I have taken a look at it I apologize for sounding rude again and I know all you are trying to do is help thank you the world needs more people like you.

Millions of people also don't have this problem. I don't know, something small thing in configuration, for example BIOS can make big difference.

I disabled Speedstep in my Bios and I haven't had a single problem with The Witcher 2 I guess that solved it :D