Windows Server 2003 - XML enable!!!

Hi

I am making my very first webserver and wanted to make a mail with both webmail interface and pop3 capabilities.
Ive tried the horde/imp system and want to use that because its a good "engine" in my opinion. Its designed for apache I know, but its all php so it should work out.

My problem is:

It needs DOM XML support to work, and I cant seem to get the bloody XML to work. Every where I go it just states that it is implemented in server 2003 through asp.net or something like that.

The "horde" people recommends the expat xml parser, but I cant get it to work.

Ive setup expat_win32bin_1_95_7.exe on my box but I dont know if it should be registered or something - currently it is just installed.

Other info:
Athlon 700 box
MyODBC 3.51
Mysql 4.20
Php 4.2.7
Pear

Note:
Ive got cygwin too, but if I need to use it to config anything, plz be VERY specific, as I have no idea how to go about linux.

Thx in advance....

Claus Lee
Newb Admin/Host