I am struggling with breakPoint issue in VS 2012 for more than hours. I am from eclipse background, there I never heard about such issues.
Problem :<
Actually there is "Modules" option, but it's enabled only when you are in debug mode. You can just press Ctrl+D,M combination when you're in debug. In few words, PDB is a file that contains all debug information about your assebmly, you can not debug an assembly without this file. Assembly is a file that contains precompiled code for exetuion via CLR. Could you provide a bit more information about your problem. What kind of application you are trying to debug for example? Also, if you have located you pdb files made EXACTLY for your assembly, you can load it by right-clicking your assembly in modules window and selecting Load Symbols From > Symbol Path