I don't quite understand what you are trying to do. Do you want it to run on top of windows or to be a complete OS? IF you want the Complete OS, then you need to start with a lower level language than VB. If you just want a forms app that looks like a different OS, you could do that, but you are going to have to draw your controls yourself. You may be able to find some controls that exists that you can repurpose, but in the end a control is just something drawn on the screen that reacts when a user interacts with in different ways.