Windows Search/Server 2008 R2

I'm confused about Windows search services within the file server role.  I seem to have 2 choices.  Windows Search and the Indexing service.  I have one main file server, 2008R2 that serves the company's document stores.  It says Windows Search is installed but trying to search any of the drives from XP/7 tells me Windows Search isn't installed.  Also, the server manager tells me Windows Search isn't suitable for Enterprise applications.

So what do I use?  Should I be using the indexing service instead?

Thanks!