> > Is it possible to put a tab control inside another tab control. I tried
I don't recommend using nested tab controls for usability reasons. If
you need to put a lot of information on one form, just use a whole lot
of tab pages. If all the information doesn't fit inside tabs on a tab
control on a 800x600-fitting form, then you need to figure out how to
split the form up into many forms.
For mega-sized forms, if you absolutely must, you can do what a lot of
software vendors do for their "Options" dialog boxes--you can put a
listbox with all the "tab headers" on the left. This can work
cleanly. When a user clicks on one of the "tab headers", you reveal
their tab somewhere to the right on the form. The implementation of
this can allow either using a subform control, or can be done via a
huge tab control. The advantage of using the tab control is that
everything is loaded at once; the disadvantage is also that everything
is loaded at once.
But it's all up to you.