Videomaker – Learn video production and editing, camera reviews › Forums › General › Video and Film Discussion › Aligning Video and Audio. › Aligning video and audio
See if you can isolate what is causing the problem. Does this occur when you play back the video in your camera? If it's o.k. when played in camera the problem is with the computer, possibly with the sound card but more than likely with the computing power of the CPU. Try playing back your video on someone elses computer and see if that makes any difference.
You definitely don't want to record the video on one device and the audio on another; unless you're using very good equipment it's very possible to have different recording rates that will create the problem you're describing. I suspect that recording the audio using one software program while capturing your video with another places a heck of a strain on your computer and may be responsible for the problem.
You don't say what the camera is, or what kind of computer hardward and software your're using. Having this information will make it easier for us on the forum to offer suggestions.