You might need to reinstall the graphics card drivers .
To get into Windows reboot the computer tapping F8 (or F5) to get to the Safe mode boot menu.
Don't use Safe Mode but instead selesct "Enable VGA Mode" and let the pc boot up.
This will boot Windows as normal with the exception of the graphics card drivers(It will use Windows built in vga drivers instead).
You can now reinstall the graphics card drivers.
Could you also give a bit more information about why and how you reinstalled DirectX 9 ?