i had the exact same issue. tried different suggested method but no luck...
eventually i found a way to get the Acrobat X Pro installed myself.
there is the procedure
1.) install CS6 package
2.) if Acrobat X Pro is failed to install then change all Windows language settings to US English
*disable Anti-Virus if needed
3.) run Photoshop once to activate the license
4.) run the CS6 installation again to install Acrobat X Pro
5.) roll back Windows language settings if Acrobat X Pro is successfully installed