Location is
http://www.microsoft.com/downloads/details.aspx?familyid=886ACB56-C91A-4A8E-8BB8-9F20F1244A8E&displaylang=en86.2MB
This is the full DirectX installer.. when you run this, it will ask for an extraction folder.. Create a new folder just for this..
After extraction, go into new folder and run Setup.exe.. this will completely overwrite previous DirectX versions and reset registry entries to where they should be.
After install is done, you can delete the downloaded file and deletel the new folder created during extraction.
restart system and your PC is now up to date with latest DirectX.
MS Web Installer skips the registry fixing and may skip DirectX files due to errors in the registry, which is why I recommend the Redistributable installer.
I also recommend keeping this file on hand (at least until the next DirectX Redistrib comes out) .. Some games use their own Redistributable installer as the game installs.. Redistribs have been known to overwrite newer DirectX versions.. as such, it is recommended to run the Latest Version after each game install to keep your system up to date.