Have you tried switching the camcorder OFF and then ON again whilst everything is coupled up as this will (or should) trigger the PC into recognising the camcorder being connected. However apart from that a number of different issues can be responsible for this but you do not give enough information to determine which is liable to apply, however in general terms its always best to use a firewire connection between the PC and the camcorder "if" the PC has a firewire connection, this also known as an IEEE1394 or DVi connection, as is the one fitted to the camcorder. If you do not have a firewire connection on the PC and are using a USB coupling to the PC then you have to use the USB streaming driver disc that came with the camcorder or you will find difficulty transferring video. The things mentioned are basics, but with this type of problem you really have to mention what operating system the PC uses, the type of cable you are using between both devices and if its USB if you have loaded the driver disc etc,etc.