Why is the Capture button disabled after connecting my DV camcorder?

This is most likely because you are using a USB wire to make the connection. In PowerEncoder MPEG-4 AVC Edition, you will need to use an IEEE1394 (Firewire) cable to capture video.

Also, check that your Operation System (OS) has recognized the added device. This can be done by double-clicking your My Computer icon. If your OS has not recognized your DV then PowerEncoder MPEG-4 can not either.