FreePCB is a free, open-source PCB editor for Microsoft Windows. It was designed to be easy to learn and easy to use, yet capable of professional-quality work.
Some of its features are: 1 to 16 copper layers, board size up to 60 inches by 60 inches, uses English or metric units (i.e. mils or mm) for most functions, footprint libraries courtesy of Ivex Design International, PCB Matrix and the IPC, and more.
It's very usable software. I have used it, but only 100 points, now I need another software for drawing more than 100 points Winboard or Windraft.