If you are having issues running DCS World, I suggest running through the following check list:
1- Start DCS World by bypassing the Steam launching process, i.e. rather than hitting Play in Steam then run directly the following..
X:\Program Files (x86)\Steam\steamapps\common\DCSWorld\bin\Launcher.exe
2- Make sure you are running the game as Admin.
3- Make sure system at least meets minimum specifications:
Minimum system requirements: OS 64-bit Windows Vista, 7 or 8; CPU: Core 2 Duo 2.0 GHz; RAM: 6 GB; Free hard disk space: 10 GB; Video: 512 MB RAM card, DirectX 9.0c - compatible; Sound: DirectX 9.0c - compatible; requires internet activation.
4- Delete the DCS Wold folder in your Users/Saved Games directory. Don't worry, the folder will be recreated when you next start the game. Note that this will reset your game option settings.
5- Turn off UAC.
6- Run Microsoft Viual C++ 2010 runtime install: http://www.microsoft.com/downloads/en/details.aspx?FamilyID=BD512D9E-43C8-4655-81BF-9350143D5867
7- Run the latest DX9c Runtime Installer: http://www.microsoft.com/en-us/download/details.aspx?id=35
8- Make sure your graphics card drivers are up to date.
9- Select "Library" in the Steam menu, right click DCS World and select "Properties". A new window will appear, here select the "Local Files" tab and select "Verify Integrity of Game Cache".
10- If your are running PlayClaw 4, shut down that program.
If your problem persists, you should consider opening a support ticket that also includes your crash log file. With that, we may be able to better disagnose your problem: http://www.digitalcombatsimulator.com/en/support/
C:\Users\ [yourusername] \SavedGames\DCS\Logs there should be crash logs and game logs.
A much more extensive support forum can be found here where you may find a solution: http://forums.eagle.ru/forumdisplay.php?f=185