Setting include directories isn't working

Tech-Archive recommends: Fix windows errors by optimizing your registry

I'm using:

cl /LD /IC:\Java\jdk1.5.0_08\include

This directory includes the file "jni.h", but cl.exe is complaining that
it can't open jni.h. I'm new to development on Windows. Am I using this
option correctly? I also tried:

cl /LD -IC:\Java\jdk1.5.0_08\include

and:

cl /LD -I C:\Java\jdk1.5.0_08\include

What's the magic here?

Thanks!
.