What application is giving you the problem? You may be able to modify the keyboard but you would never be able to use the insert key the way it was designed for toggling insert / override. You would always be doing one or the other and that would just make typing into a program like word, notepad or other text editor a real nightmare. If using Word try going to FILE > OPTIONS > ADVANCED and in the editing section there are options on setting the use of the INSERT key.
Better yet, create a new keyboard layout that does not use the insert key and then you can switch keyboard layouts as needed. For step on how to create a new one and switch back and forth check out this link