fix computer errors

When trying to covert a video file onto disk using DVD Flick about one third into the process the error message, ffmpeg.exe has stopped working and needs to close appears. I also have K Lite codec pack. I have removed both programs and reinstalled but still the same. When I first installed the programs it worked fine for one disk, then the problems began. My husbands computer has both programs and works like a charm, he also has Vista which might make a difference.. Any suggestions would be so much appreciated. Thanks… PS I have just basic PC knowledge