Part 1. Having an Audio Delay and you only want to watch the movie on your PC
Part 2. Having an Audio Delay and AviMuxGui recognise it.
Part 3. Having an Audio Delay and AviMuxGui doesn't recognise it.
Part 1.
You have an audio delay and you only want to watch the movie on your pc. Well in that case you don't need to fix the audio delay. You can use the settings in the programm you use to watch the movie. I'll show you here where you can find the settings on the programm Media Player Classics. For other programms use their guide.
Media Player Classic
Click on play, audio and then options. You will see next screen:

check the box of Audio Time Shift and fill in the audio delay in milli secconds. Push ok and you're done, you can watch the movie with delay now. Remember the avi isn't fixed. So if you burn it to dvd or convert it there will still be a delay. The next two parts will definitly fix the avi.

Part 2
I will explain here how to fix an audio delay in your avi with AviMuxGui.
It is easy to use and it's fixing the delay real fast. Most important though it is free as well.
You can download it by clicking Here!
Run AviMuxGui and you'll see this screen:

Now Rightclick in the topbox and after that click on add.
Choose your avi which has the delay as shown in the next screen:

After that your screen of AviMuxGui will look like this:

Select the Avi in the topbox in AviMuxGui by clicking on it. It will become blue.

Click the button "generate data source from files" and you'll get next screen:

In the bottom box at the audio line (the seccond line) you allready see it has an audio delay of 26ms.
If you click on that line the line becomes blue and the delay will become visible in the box next to that line on the right.

Click on start and choose a name for the new avi file (it must be different as the source name)

push save as: and in a minute of three you'll have yourself a fixed Avi.

Part 3
Ok a different one, You have an audio delay. opened the avi in AviMuxGui and there is no audio delay according to AviMuxGui. It happens sometimes mostly with your own rips. In that case the delay is almost always 500ms and sometimes 1000ms. Try to find out the delay in ms using the methods explained in part 1. If you found the delay in ms open the avi in AviMuxGui and generate data source from file as explained in part 2. You'll get a screen like the one below:

Fill in the delay in ms in the box at the right of the line of the default audio like in the next screen:

Then push start and from there follow the same instruction as told in part 2 after pushing start. And again you'll have a fixed Avi.