Suddenly Can’t Open JPEG Files

After several years opening JPEG files from my digital camera and from those attached to email, I can’t open them. The message states that it can not find PictureViewer.exe, which I don’t believe I ever had. I do have the following files: jpeg1x32.dll, jpeg2x32.dll, and jpegim32.flt. I tried rebooting but still could not open the jpeg files.