I have same thing. I launch game from Steam, get launcher window, click play, get black screen and pc freezes. Have to switch power off.
Like previous poster, I don't have settings.txt and from log-files only system.log has something on it.
I tried to force it to 640x480 mode, administrator mode, XP-compablitymode. Nothing helps. I have lots of games on Steam and Origin and etc, they all work fine.
Below is Dxdiag and system.log
Dxdiag
------------------
System Information
------------------
Time of this report: 5/27/2012, 13:14:12
Machine name: NILJA-PC
Operating System: Windows 7 Ultimate 64-bit (6.1, Build 7600) (7600.win7_rtm.090713-1255)
Language: Finnish (Regional Setting: Finnish)
System Manufacturer: Gigabyte Technology Co., Ltd.
System Model: GA-790XTA-UD4
BIOS: Award Modular BIOS v6.00PG
Processor: AMD Phenom(tm) II X4 965 Processor (4 CPUs), ~3.4GHz
Memory: 12288MB RAM
Available OS Memory: 12286MB RAM
Page File: 2359MB used, 22212MB available
Windows Dir: C:\Windows
DirectX Version: DirectX 11
DX Setup Parameters: Not found
User DPI Setting: Using System DPI
System DPI Setting: 96 DPI (100 percent)
DWM DPI Scaling: Disabled
DxDiag Version: 6.01.7600.16385 32bit Unicode
------------
DxDiag Notes
------------
Display Tab 1: No problems found.
Sound Tab 1: No problems found.
Sound Tab 2: No problems found.
Input Tab: No problems found.
--------------------
DirectX Debug Levels
--------------------
Direct3D: 0/4 (retail)
DirectDraw: 0/4 (retail)
DirectInput: 0/5 (retail)
DirectMusic: 0/5 (retail)
DirectPlay: 0/9 (retail)
DirectSound: 0/5 (retail)
DirectShow: 0/6 (retail)
---------------
Display Devices
---------------
Card name: AMD Radeon HD 6800 Series
Manufacturer: Advanced Micro Devices, Inc.
Chip type: ATI display adapter (0x6738)
DAC type: Internal DAC(400MHz)
Device Key: Enum\PCI\VEN_1002&DEV_6738&SUBSYS_00D01002&REV_00
Display Memory: 2795 MB
Dedicated Memory: 1004 MB
Shared Memory: 1791 MB
Current Mode: 1920 x 1200 (32 bit) (60Hz)
Monitor Name: Generic PnP Monitor
Monitor Model: BenQ G2400W
Monitor Id: BNQ780A
Native Mode: 1920 x 1200(p) (59.950Hz)
Output Type: DVI
Driver Name: aticfx64.dll,aticfx64.dll,aticfx64.dll,aticfx32,aticfx32,aticfx32,atiumd64.dll,atidxx64.dll,atidxx64.dll,atiumdag,atidxx32,atidxx32,atiumdva,atiumd6a.cap,atitmm64.dll
Driver File Version: 8.17.0010.1124 (English)
Driver Version: 8.961.0.0
DDI Version: 10.1
Driver Model: WDDM 1.1
Driver Attributes: Final Retail
Driver Date/Size: 4/6/2012 05:20:04, 1067520 bytes
WHQL Logo'd: n/a
WHQL Date Stamp: n/a
Device Identifier: {D7B71EE2-2478-11CF-D677-DA20BEC2C535}
Vendor ID: 0x1002
Device ID: 0x6738
SubSys ID: 0x00D01002
Revision ID: 0x0000
Driver Strong Name: oem43.inf:ATI.Mfg.NTamd64.6.1:ati2mtag_NI:8.961.0.0

ci\ven_1002&dev_6738
Rank Of Driver: 00E62001
Video Accel: ModeMPEG2_A ModeMPEG2_C
Deinterlace Caps: {6E8329FF-B642-418B-BCF0-BCB6591E255F}: Format(In/Out)=(YUY2,YUY2) Frames(Prev/Fwd/Back)=(0,0,1) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_PixelAdaptive
{335AA36E-7884-43A4-9C91-7F87FAF3E37E}: Format(In/Out)=(YUY2,YUY2) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_BOBVerticalStretch
{5A54A0C9-C7EC-4BD9-8EDE-F3C75DC4393B}: Format(In/Out)=(YUY2,YUY2) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY
{6E8329FF-B642-418B-BCF0-BCB6591E255F}: Format(In/Out)=(UYVY,UYVY) Frames(Prev/Fwd/Back)=(0,0,1) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_PixelAdaptive
{335AA36E-7884-43A4-9C91-7F87FAF3E37E}: Format(In/Out)=(UYVY,UYVY) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_BOBVerticalStretch
{5A54A0C9-C7EC-4BD9-8EDE-F3C75DC4393B}: Format(In/Out)=(UYVY,UYVY) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY
{5A54A0C9-C7EC-4BD9-8EDE-F3C75DC4393B}: Format(In/Out)=(YV12,0x32315659) Frames(Prev/Fwd/Back)=(0,0,0) Caps=
{3C5323C1-6FB7-44F5-9081-056BF2EE449D}: Format(In/Out)=(NV12,0x3231564e) Frames(Prev/Fwd/Back)=(0,0,2) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_PixelAdaptive
{552C0DAD-CCBC-420B-83C8-74943CF9F1A6}: Format(In/Out)=(NV12,0x3231564e) Frames(Prev/Fwd/Back)=(0,0,2) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_PixelAdaptive
{6E8329FF-B642-418B-BCF0-BCB6591E255F}: Format(In/Out)=(NV12,0x3231564e) Frames(Prev/Fwd/Back)=(0,0,1) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_PixelAdaptive
{335AA36E-7884-43A4-9C91-7F87FAF3E37E}: Format(In/Out)=(NV12,0x3231564e) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_BOBVerticalStretch
{5A54A0C9-C7EC-4BD9-8EDE-F3C75DC4393B}: Format(In/Out)=(NV12,0x3231564e) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY
{5A54A0C9-C7EC-4BD9-8EDE-F3C75DC4393B}: Format(In/Out)=(IMC1,UNKNOWN) Frames(Prev/Fwd/Back)=(0,0,0) Caps=
{5A54A0C9-C7EC-4BD9-8EDE-F3C75DC4393B}: Format(In/Out)=(IMC2,UNKNOWN) Frames(Prev/Fwd/Back)=(0,0,0) Caps=
{5A54A0C9-C7EC-4BD9-8EDE-F3C75DC4393B}: Format(In/Out)=(IMC3,UNKNOWN) Frames(Prev/Fwd/Back)=(0,0,0) Caps=
{5A54A0C9-C7EC-4BD9-8EDE-F3C75DC4393B}: Format(In/Out)=(IMC4,UNKNOWN) Frames(Prev/Fwd/Back)=(0,0,0) Caps=
{5A54A0C9-C7EC-4BD9-8EDE-F3C75DC4393B}: Format(In/Out)=(S340,UNKNOWN) Frames(Prev/Fwd/Back)=(0,0,0) Caps=
{5A54A0C9-C7EC-4BD9-8EDE-F3C75DC4393B}: Format(In/Out)=(S342,UNKNOWN) Frames(Prev/Fwd/Back)=(0,0,0) Caps=
D3D9 Overlay: Not Supported
DXVA-HD: Not Supported
DDraw Status: Enabled
D3D Status: Enabled
AGP Status: Enabled
-------------
Sound Devices
-------------
Description: Kuulokkeet (ASUS Xonar DG Audio Device)
Default Sound Playback: Yes
Default Voice Playback: Yes
Hardware ID: PCI\VEN_13F6&DEV_8788&SUBSYS_84671043&REV_00
Manufacturer ID: 1
Product ID: 100
Type: WDM
Driver Name: cmudaxp.sys
Driver Version: 5.12.0001.0008 (English)
Driver Attributes: Final Retail
WHQL Logo'd: n/a
Date and Size: 3/10/2011 15:44:16, 2725376 bytes
Other Files:
Driver Provider: ASUSTeK
HW Accel Level: Basic
Cap Flags: 0x0
Min/Max Sample Rate: 0, 0
Static/Strm HW Mix Bufs: 0, 0
Static/Strm HW 3D Bufs: 0, 0
HW Memory: 0
Voice Management: Yes
EAX(tm) 2.0 Listen/Src: Yes, Yes
I3DL2(tm) Listen/Src: No, No
Sensaura(tm) ZoomFX(tm): No
Description: Digital Output (ASUS Xonar DG Audio Device)
Default Sound Playback: No
Default Voice Playback: No
Hardware ID: PCI\VEN_13F6&DEV_8788&SUBSYS_84671043&REV_00
Manufacturer ID: 1
Product ID: 100
Type: WDM
Driver Name: cmudaxp.sys
Driver Version: 5.12.0001.0008 (English)
Driver Attributes: Final Retail
WHQL Logo'd: n/a
Date and Size: 3/10/2011 15:44:16, 2725376 bytes
Other Files:
Driver Provider: ASUSTeK
HW Accel Level: Basic
Cap Flags: 0x0
Min/Max Sample Rate: 0, 0
Static/Strm HW Mix Bufs: 0, 0
Static/Strm HW 3D Bufs: 0, 0
HW Memory: 0
Voice Management: No
EAX(tm) 2.0 Listen/Src: No, No
I3DL2(tm) Listen/Src: No, No
Sensaura(tm) ZoomFX(tm): No
System.log
[systemsettings.cpp:181]: System memory: 0MB
[systemsettings.cpp:183]: CPU speed: 3415MHz
[systemsettings.cpp:190]: Number of processors: 4
[systemsettings.cpp:201]: CPU type: x86
[systemsettings.cpp:233]: OS: Unknown Build: 7600
[gfx_settings.cpp:51]: Graphic Adapters:
[gfx_settings.cpp:56]: 0: AMD Radeon HD 6800 Series
[gfx_settings.cpp:73]: Checking for multi-sampling support:
[gfx_settings.cpp:84]: 2 samples supported.
[gfx_settings.cpp:84]: 4 samples supported.
[gfx_settings.cpp:84]: 8 samples supported.
[gfx_settings.cpp:99]: Using Adapter [0]:
[gfx_settings.cpp:105]: Succeeded to create a device [D3DCREATE_HARDWARE_VERTEXPROCESSING].
[gfx_settings.cpp:147]: Graphics device: AMD Radeon HD 6800 Series
[gfx_settings.cpp:148]: Graphics driver: aticfx32.dll
[gfx_settings.cpp:153]: Driver version: 1124
[gfx_settings.cpp:170]:
Dumping all gfx info:
DeviceIdentifier: {D7B71EE2-2478-11CF-D677-DA20BEC2C535}
VendorId: 4098
DeviceId: 26424
SubSysId: 13635586
Revision: 0
DriverVersion.HighPart: 524305
DriverVersion.LowPart: 656484
[gfx_settings.cpp:220]: Instancing supported.
[gfx_settings.cpp:238]: Video memory amount: 1342MB
[gfx_settings.cpp:241]: Support for T&L found.
[gfx_settings.cpp:244]: MaxSimultaneousTextures: 8
[gfx_settings.cpp:245]: MaxVertexBlendMatrices: 4
[gfx_settings.cpp:246]: MaxVertexBlendMatrixIndex: 8
[gfx_settings.cpp:248]: MaxSimultaneousTextures: 8
[gfx_settings.cpp:249]: MaxTextureBlendStages: 8
[gfx_settings.cpp:250]: Support for Anisotropic filtering found.
[gfx_settings.cpp:253]: Max Anisotropic filtering: 16
[gfx_settings.cpp:254]: Anisotropic filtering set to: 0
[gfx_settings.cpp:258]: Vertex Shader version: 3.0
[gfx_settings.cpp:263]: Pixel Shader version: 3.0
[main.cpp:442]: CK2 Version May 16 2012 : 13:45:47
[internationalizedtext.cpp:1244]: Create table
[internationalizedtext.cpp:1246]: Create text database
[graphicssettings.cpp:624]: Not using multisampling.
[graphics.cpp:163]: Creating device with: HARDWARE_VERTEXPROCESSING
Fullscreen=yes
RefreshRate=60
Resolution=1920x1200