How to check DirectX version?

• Using "dxdiag"
  
  In Windows 8:
  1. Click "Win + R" to open the Run dialog box
  2. Type: dxdiag, and press enter, look for Direct X version line in dialog that opens
  In Windows 7, Vista and XP:
  1. Click "Start" button and click "Run"
  2. Type: dxdiag, and press enter, look for Direct X version line in dialog that opens
  
  
• Using "DirectX Version Checker"
  
  A freeware utility to check the DirectX version:
  1. Download mirror: DirectX Version Checker
  2. Install and run program

How to update DirectX in Windows?

• DirectX End-User Runtime Web Installer
  
  If you need the latest DirectX version, the simplest way to update the DirectX on your Windows is download and use the "DirectX End-User Runtime Web Installer" from microsoft.com, it provides updates to 9.0c and previous versions of DirectX - the core Windows technology that drives high-speed multimedia and games on the PC.
  
  Download: DirectX End-User Runtime Web Installer
  
  

Frequently Asked Questions about DirectX update

• Will DirectX 11 be available for Windows Vista or Windows XP?
  DirectX 11 is built into Windows 7, and it is available as an update for Windows Vista. For the same reasons noted in the preceding question, Direct3D 11 and related APIs are not available on Windows XP.
  
  
• What changes were made to the DirectX runtime for Windows 8/7?
  Windows 8/7 includes all of the DirectX runtime components found in Windows Vista, and adds Direct3D 11, DXGI 1.1, 10Level9 feature levels, the WARP10 software device, Direct2D, DirectWrite, and an update to Direct3D 10.1 to support 10Level9 and WARP10.