Hi there, as it has already been said, there are a great many PCB packages that use .PCB for its file extensions. Try opening the file with a text editor (hold down shift, right click & use "open with" then select notepad) and have a browse around inside. They usually put some text in to identify them. Matthew Lamkin. --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------