You can configure your Garritan library with Sibelius by following these steps:
Make sure the Garritan library is activated and the ARIA Player is updated to the latest version.
With a document open, click the Play Tab, then click the Playback devices icon (just below Mixer).
With the Playback Devices window open, click the New… button to create a new configuration, name it, and click OK.
Choose the ARIA player in the Available Devices column and click Activate to add it to the Active Devices. (If the ARIA player is not showing, follow the steps in this article.)
You can choose the Garritan libraries as Preferred Sounds, Sound Sets and Effects by selecting the appropriate tab and selecting those devices. (For questions on obtaining sound sets, please visit the Sibelius website.)
Click Close and Save the changes.
You should now get playback through the ARIA Player. mario games
----what an odd post. It seems like reasonable Sibelius/Garritan advice, but with a link to a totally off-topic gaming site, and the user name posted is the same as that site.
HMmmmm - well, if you were sincerely wanting to help Sibelius users, "Mariogames," that's great. It's best to post that kind of info in the General Discussion Forum. This is The Listening Room, reserved for Forum members posting their music projects.