directx problems

i cleared out my whole computer a couple of days ago and
at that time my directx was working perfectly. now when i
try to play games like red faction and warcraft where
directx is needed i get an error messege when it is
launching like.. directx: device failed or "cannot find
directx on your computer" and i know i have it because i
intalled directx 9.0 several times from microsoft. so it
would be deeply helpful if you could respond. *thank you*