(Missing DLL file)check before allowing a party to form.

d3dx9_39.dll file missing after I reinstalled windows cause of a internet issue.... I just went into a game and now can't get in. Tried repairing didnt fix it so... now im either going to have to reinstall league of legends.... on my 7 down 1 up internet... or waiting for some help on this issue... while making those 4 other people not have a fair game >.<

Would it not be possible to code it so that the launcher just doesn't launch if this file is missing?