You're using visual studio, I assume? PDB are debug files. They are generated when you compile a debug copy (the default) and allow you to do debugging features such as breakpoints. They should not be created if you set it compile the release edition.
I can't tell you exactly how to change it back, since VS has hated my last 2 computers for odd reasons, *ALWAYS* giving a registry error, and trying to fix it nearly destroyed my computer and forced me to revert (currently, the only way to make a project is to make a copy of a blank project and open that). Anyway, I used "batch build" from the build manager, unticking the "debug" version and ticking the "release" version.
Wish I could test it, but problems prevent me from doing so.