Darrel recommends storing the INCLUDES along with the PBP executable. But that folder is large and contains a lot of stuff, and it makes it harder to keep track of your INCLUDES.

I use a centralized folder C:\PBP Includes, and keep all my files in one place. They can be accessed easily:

Code:
include     "C:\PBP Includes\DT_INTS-14.bas"
include     "C:\PBP Includes\ReEnterPBP.bas"

It makes it so much easier to keep track of the modified INCLUDES. You can put that folder wherever you want; your project, C:\PBP3_1, wherever you want as long as you use the matching folder name in PBP.