While there are many Viewer Tools available for PCB layout, the PADS Viewer from Siemens has been tried and tested successfully with most of our Demo Board .PCB file extensions.
Once the PADS viewer has been downloaded and installed, either double click on the .PCB file to open it or:
Open PADS Layout viewer, then click import > select the .pcb file to be viewed. If it is not visible, change the file type to CAD STAR PCB design files (.pcb)