SharePoint uses iFilters to index its files. Filters for most common file types are included out of the box with most versions of SharePoint. The big notable exception is an iFilter for PDF files. This is because Adobe won’t let Microsoft redistribute any of their code. It’s so bad that Microsoft can’t even include a PDF icon with SharePoint, you have to go out, download it, and set it up yourself. This has been true since the early days of SharePoint.
One of the things that you must do when you configure SharePoint to index PDF files is that you must tell the indexer that PDF is a valid file type. That’s easy enough to do from within the Shared Service Provider (for 2007) or the Search Service Application (for 2010), but the free versions of SharePoint, WSS and SharePoint Foundation don’t come with these tools.
It has always been possible to do this with WSS with a little bit of registry editing (and it’s supported by Microsoft), but that’s no longer true with SharePoint Foundation. That hack just doesn’t work with it. So what’s the answer? Well, as it turns out, the solution isn’t just adequate, it’s quite a bit better. The solution is to Install Search Server Express 2010.
Search Server Express is pretty simply a (only slightly) scaled back version of the Search Service applications that you get when you install SharePoint Server 2010. They are virtually the same architecturally and you get many of the features that you get with Server 2010. You also get a few other SharePoint Service applications, most notably, the Secure Store Service. And if you’re a Foundation user,it aligns up with your licensing agreement because it’s free.
So essentially,you get a much better search engine, with more capability for free. I can’t see a down side here. You don’t already need Foundation installed to install SSE, so in the future, whenever called upon to install SharePoint Foundation, I’ll be going straight to Search Server Express.