If you write
include "/forums/ssi.php";
You'll get C:/forum/ssi.php3, I don't think that's what you want...
Suppose your script is in c:/apache/htdocs/, this should work :
include "./forums/ssi.php";
If you are in c:/apache/htdocs/forums/, this should also work :
include "./ssi.php";
Where's the difference with before ? Do you see the point before the first slash ? That point tells PHP to go in directories contained in the current directory.
Now, does it work ?
Ah, yeah, also...
If you write :
include "forums/ssi.php";
You will get c:/dir/dir/forums/ssi.php3 since you set include_path to c:/dir/dir. By the way, if in a script you write a backslash (), don't forget to espace it : \, but I suggest you to do like I do : use slashes /. It works great on Windows (well, for me...) !