1. Click Start.
2. Go to All Programs.
3. Then go to MATLAB.
4. Click on the folder for the MATLAB release that you wish to activate (e.g., R2008a). 
5. Select the option to Activate MATLAB.

You can also launch the activation client directly by running activate_matlab.exe from $MATLABROOT\bin\win64. You can find $MATLABROOT\bin\win64 in the MATLAB installation folder.

To launch the activation client, you will need to use the activate_matlab.sh script in the $MATLABROOT\bin folder. To launch this script, follow the subsequent steps:

1. Open a Terminal window.
   • On Mac OS X, go to Applications 
     ➤ Utilities 
     ➤ Terminal.
2. In the Terminal window, run the following commands:

cd $MATLABROOT/bin

./activate_matlab

You can find $MATLABROOT\bin\win64 in the MATLAB installation folder.

Note: You may need administrator or superuser permissions in order to complete activation.

For MATLAB 7.8 (R2008b) and later on Mac OS X, you can also launch the activation client from Finder, as outlined below:

1. Open a Finder window.
2. Locate the MATLAB.app icon in your Applications folder (e.g., MATLAB_R2008b.app).
3. Open the MATLAB folder by pressing Ctrl + click (or right-click).
4. Select Show Package Contents.
5. Double-click on Activate in the MATLAB folder to start the activation client.

You can also launch the activation client directly by running activate_matlab.exe from $MATLABROOT\bin\win64. You can find $MATLABROOT\bin\win64 in the MATLAB installation folder.