Apache Modules

I have been trying to use mod_rewrite in Apache 2. The problem is
that it is not installed. When I look in my "modules" directory there
is only one .so file and that is the "libphp4.so".


So, apearently all of the modules did not get installed during my
initial install. Now.. How can I get the other modules installed so I
can use them?


Thank you in advace...