To check if mod_rewrite is loaded, log in as root and issue the following command:
httpd -M
You might have to find the location of httpd to do this, to do that, try typing
whereis httpd
and see if it finds anything. Once you get a list from httpd -M, verify that rewrite_module is among the loaded modules.
If it's not, you'll have to configure Apache to load the module. To do that you'll need to have a line like
LoadModule rewrite_module modules/mod_rewrite.so
somewhere in httpd.conf. It's probably commented it, so see if you can find it in there somewhere before you add it yourself.
Hope that wasn't too fast.
