I can not download photo's from camera to PC?

I have a Samsung S1065 Camera and have been using it for about 6 months without any problem, downloading my photo's to the computer, but when I plugged my camera into the computer yesterday to download some photo's nothing happened what so ever, it did not seem to connect and I could not download, or even see the photo's on the PC screen, can you offer any help as to what has happened and how to cure it.