Position of WPF windows


I need help on WPF...

When user move/drag/change the position of the 1st page window (mainwindow.xaml), then user click on "next" button to proceed to 2nd page(process.xaml), the window (process.xaml) is not at the same position as the (mainwindow.xaml) that the user move to earlier on. How can I make it to remember the position of the window throughout? And when user close the window, and run it again, the window will be default appear in the center unless user move the window.

Really need help for this. Thanks.

Maybe it would be easiest to only have one window throughout the whole application, but replace the window's contents? Create your screens as usercontrols instead, then set content on the main window instead of opening a new one..