The Find Symbol pane of the Options dialog box specifies where the debugger will look for source files when debugging the solution.
Look for source files in the following directories
This box contains a list of directories in which the debugger searches for source files when debugging the solution.
Do not look for these source files
In this box, you can enter the names of any source files that you do not want the debugger to read. If the debugger finds one of these files in one of the directories specified above, it will ignore it.