Windows 7: Install DirectX 9 when I have 11?

When I try to run Guitar hero world tour,there's an error saying d3d#@*&^.dll missing.
I googled and found that I need install DirectX9.

My question is:Won't it cause problem since I have DirectX 11 installed already?

BTW,the game is not that old,then how come DirectX 11 can't do 9's job?



Thanks!

No it won't.

No because DirectX 11 is not DirectX 9.

Number 5 and 6 here,

Tips on Troubleshooting Game Issues

should explain it, and here is the link to the latest DirectX update,

Download details: DirectX End-User Runtime

Thank you. I didn't know it was a common issue,otherwise I could have saved the post. Thanks again anyway.

Not a problem and you're welcome.

Edit: For what it's worth I just had to do the same thing on an old computer for my kids. I just installed Windows 7 HP on it yesterday and today I installed Halo on it for my son, and had to install the DirectX files as the game didn't install them itself (which on XP it would have, but didn't on 7).