just above the big list of windows extentions is this section
;;;;;;;;;;;;;;;;;;;;;;;;;
; Paths and Directories ;
;;;;;;;;;;;;;;;;;;;;;;;;;
; UNIX: "/path1:/path2"
;include_path = ".:/php/includes"
;
; Windows: "\path1;\path2"
;include_path = ".;c:\php\includes"
; The root of the PHP pages, used only if nonempty.
doc_root =
; The directory under which PHP opens the script using /~usernamem used only
; if nonempty.
user_dir =
; Directory in which the loadable extensions (modules) reside.
extension_dir = ./ is the section to update
with the path to the extentions folder in the php folder
hth