Viewing Digital Pics from cd

I copied some pics from my digital camera to a cd with my cd writer and was able to view them on my pc. Thought everything was ok so took the disc to my neighbor and they tried to view them on their pc and a program came up called picture viewer and we could not get the pics to run. Why cant we get the pics to come up. He has never used this picture viewer before. Can someone help me on this. I saved the pics in my documents first and then burned them on the cd. Can someone help me on this. Thank you Sami