"Windows Media Player Network Sharing" - Not listed in services.ms

Hello
I'm trying to use WMP11 as a media server, to allow my PlayStation 3 to
stream my media library.
The problem is, Windows Media Player Network Sharing Service is not present
in my services list.
I know it used to be there, as i disabled it from runniing automaticaly when
i didn't need the service.
I have no idea how this could have happened, and can't seem to find any
solution.
I cannot uninstall WMP, as it's not listed in appwiz.cpl
I tried to re-install WMP11 but the one available from MS downloads section
can't be installed, here's the error message i get when i try:
"There is a more recent version of windows media player (11.0.6002.18005)
already installed on your computer."
I'm assuming this is due to the media player on my laptop is an OEM version
from ACER?
Can somebody please tell me how to resolve this problem & get the service
back in my list.
I'll be eternally greatfull.