Direct X is part of the Windows operating system.
Hit start and type in "dxdiag" in the "search programs and files" spot and hit return. Then when the wondow opens, hit the "save all information: button which will create a text file. open the txt file in Notepad and you will see something like:
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System Information
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Time of this report: 12/20/2009, 11:21:39
Machine name: [your machine name]
Operating System: Windows 7 Ultimate 64-bit (6.1, Build 7600) (7600.win7_rtm.090713-1255)
Language: English (Regional Setting: English)
System Manufacturer: Dad
System Model: Son No. 2's Rig
BIOS: BIOS Date: 11/03/09 13:28:23 Ver: 08.00.15
Processor: Intel(R) Core(TM) i7 CPU 920 @ 2.67GHz (8 CPUs), ~2.7GHz
Memory: 6144MB RAM
Available OS Memory: 6136MB RAM
Page File: 1919MB used, 11382MB 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 64bit Unicode