Download and install YAAI from SourceForge.
Launch YAAI. Locate the AVI file in the "Open avi" dialog box of YAAI. Click to highlight this file and click on the "Open" button.
Click on the "Sync Audio" tab and the "YAAI Avi Player" will appear. Carefully watch and listen to the AVI file in order to establish whether the audio is ahead of video or behind the video. Adjust the "Delay Video/Audio" slider by clicking and dragging the slider or by using the plus and minus buttons.
Click "Apply" and preview the video in the "YAAI Avi Player" to establish whether or not the delay settings are correct. You may adjust the settings and click "Apply" to preview as many times as needed until the AVI is properly synced.
Close the YAAI program. A "Confirm" dialog box will appear. Click "Yes" to save the sync changes you have made to the AVI.
Download and install VirtualDub from SourceForge. Launch the program.
Click on "File." In the drop down select "Open video file." Locate the AVI file in the "Open avi" dialog box. Click to highlight this file and click "Open."
Click on "Audio" from the menu. In the drop down menu select "Interleaving."
Type a value in milliseconds in the "Audio skew correction" box. The milliseconds should correspond with the amount of time the lip sync is off. Use a minus sign when entering the milliseconds if the audio is trailing the video. Enter positive numbers if the audio is ahead of the video.
Click "OK" then click "File" from the menu. In the drop down select "Save as AVI."
Download and install AVIMux GUI from SourceForge. Launch the program.
Open the folder containing the AVI file. Drag and drop it in the upper "open files" box in AVIMux GUI.
Click on the AVI file in the "open files" box to highlight it. Click on "Generate data source from file."
Click on the "audio" stream that appears in the lower box.
Type a value in milliseconds in the "delay" box. The milliseconds should correspond with the amount of time the lip sync is off. Use a minus sign when entering the milliseconds if the audio is trailing the video. Enter positive numbers if the audio is ahead of the video.
Click "Start" and a "Save As" box will appear. Select the desired destination folder and title your AVI. Click "Save."