DipTrace Free
DipTrace is an advanced PCB design software application that comes with a PCB Layout module, a powerful auto-router, Schematic Capture and Component/Pattern editors to design your own component libraries. Besides being very simple to learn, which is quite an accomplishment for an engineering... A net connectivity check allows you to check all electrical connections and find all broken nets and their isolated areas. ... A feature comparing a PCB to a schematic helps detect possible design mistakes and correct them before prototyping.
http://www.diptrace.com/downloads/dipfree_en.exe - 16Mb - Download - Screenshot