You can remove the path of the toolbox that you do not want loaded from MATLAB search path. To find the path of all the toolboxes installed use the command:
To remove that path of a specific toolbox, use the command:
>> rmpath('put the path of the toolbox here')
For example, to remove the Wavelet Toolbox you can execute:
>> rmpath([matlabroot '\toolbox\wavelet\wavelet'])
In order to avoid executing this command every time you start MATLAB, either use savepath or add the 'rmpath' command in your 'startup.m' file. In order to restore the path of a specific toolbox use addpath . Alternatively, you can restore the default paths of all your toolboxes using the commands:
>> rehash toolboxcache
Please note that restoring the default toolboxes path will delete the path to any custom toolbox that you might have already added and you will have to re-add them.
I hope this helps.