I have tried to use direcx9.0c on my friend computer. Many bugs fixed expecially when playing the old game like red alert 2. I mean the game run smoothly. If you really want to install it this is how you must do.But you must have installer for direcx9.0b and directx9.0c.
first step
extract the directx 9.0b in one folder
second step
extract the directx 9.0c into the other folder
third step
notice all the *.cab file in the directx 9.0c folder
forth step
copy all the *.cab file from directx9.0c and replaced it in the folder for directx9.0b
final step
install the intaller in directx 9.0b
and walla, you with have directx9.0c already install in your computer with all the updated file!!
this will definitely install directx 9.0c and fully workble without any error
from:manlaju