No Exit Point in Wizard Design

When I went through the process of transitioning from hotmail to Windows Live Mail Beta, I noticed that the wizard only had the "Continue" button. There was no way to get out except for closing the browser. Even the top logo was not linked to anywhere.

I had no problem of going through the wizard to make the transition successful. However, this design deviates from what we usually advocate/a usability principle: Always clearly mark the exit point in a process/wizard.

I guess in this case, it is a way of discouraging the user to exit the wizard/or encourage the user to complete the process.

Do you have any success or lessons for this design method?

Thanks!

- Cindy