Unresolved reference SPI.h

I just started using Arduino with eclipse, followed the installation guide and successfully executed the Blink program. I want to use SPI.h but getting an error as Unresolved reference. I have included 'C:\Program Files (x86)\Arduino\libraries' for my project. Not sure why I am getting the error?

Me neither - if you included the full text of the error message and the code you're encountering the error with, we could probably help.

Also - what board are you using?

I was getting an error "Unresolved reference <SPI.h>" while including standard SPI library. I am using Arduino plugin in eclipse so had to explicitly add the SPI library. Below post helped me resolve the issue.

http://forum.arduino.cc/index.php?topic=329225.0