Hardware and performance

Hi
I've hunted high and low and can't find a definitive answer. What modules in apache 2.2 on a Windows 2003 server do we definitely need to load in order to run Moodle?
I can see from the Apache manual what the modules do, but that isn't helping because I don't know what Moodle uses to run.
I've seen this thread:-
http://moodle.org/mod/forum/discuss.php?d=68696#p308698
which seems to list the modules they are using, but I can't tell from the forum thread whether that config is actually working properly or not.

We are suffering performance issues hence the thought that it was time to stop loading stuff we don't need.
Guidance would be wonderful.
Thanks