I have decided to write my own combobox control by using a custom listbox that will appear in a popup window. The thing that i was trying to achieve was to have it in such a way so that the popup window doesn't steal the focus from the main form. Apparently however, the dotnet framework has a system that sets the focus whenever you click on a windows forms control. So, the only way to do it is to override the WndProc method and go from there. I think i will do a whole dotnet library of custom controls and components based on this idea.