I had an issue with DirectX 9 and I wanted to uninstall or downgrade the version. After searching for a while I found that it is impossible to uninstall the DirectX from Windows since windows is shipped with DirectX. The only option is to downgrade the version.
This following step will help you to downgrade the DirectX version to 8.1.
You need your Windows XP CD.
1. Go to Major Geeks website, and download directx-dx9uninstaller.zip
2. Extract these files to C:\DXTEMP
3. Now Re-boot your machine to Safe mode
4. Now keep the Windows CD in the drive
5. Run the UnDx9.bat file located inside C:\DXTEMP
6. Enter the CD drive letter first
7. And enter the i386 folder path in the CD like G:\i386\
8. Now, It is having 3 steps what you want to do is just Hit Enter when ever it asks.
Reboot the machine to the normal version and check the directX version, it will be 8.1 now.