Please see my comment to the question. Practically, you can consider it as the main and most principle part of the answer. However, I want to avoid accusation in relying on individual taste (which of course would not be correct), so this is still a "personal" comment.—SA
So, here is the real answer: yes and no.
Yes, because you can imitate any style you want, pixel by pixel. In turn, this is possible because you can always handle so-called "non-client" windows message which actually define the rendering of all of the style elements of all windows, by you also would need to do custom rendering of all standard controls, because they are also the subjects of styles. This can be done via custom drawing and/or handling of the
WM_PAINT messages. Before we move the the "no" aspects, note that this would be very difficult; and a lot of (purposeless) work. Also, is it solution or not? It depends on the exact meaning of "display with XP style". At least, you can reproduce and preexisting style, in principle, but this is not the universal solution.
No, because if the user disables the styles globally, it is done on purpose and handled by Windows properly. In other words, there is some kind of "style engine" which is bypassed as a whole thing. After that, some "default" styles are left, such as default old W2K style and default XP style. Usually, the support of styles means that the user can create some custom style merely composed of the same style elements, optional colors, etc., all together maintaining some stylistically consistent solution (I never saw users able to make something really attractive out of it, but this would be, again, a matter of individual taste, something I want to avoid; what is important, this feature formally works this way, providing this kind of custom choice). If this is something you really want, you cannot achieve that, even if you do all the work described in the above "yes" paragraph. Besides, it's almost impossible to predict how some style element will look in all modes before you actually try it, so the imitation I described above cannot be reliable, to say the least.
General conclusion: even though you can do something to approach the goal, it has very little practical sense; and I would probably prefer to say: no sense at all.