Windows 7 Explorer: Open in same window

I didn't find any sort of registry fix for this, but I did notice that if you use the hierarchy sidebar to change folders instead of clicking on the folder's icon, the new folder will open in the same window.

Edit: I apparently never posted the original topic. I was referring to a problem I was experiencing in Windows 7: Professional where I had set the folder options in Windows Explorer to open in the same window, but every time I opened a new folder, a new window would open to accommodate it.