I'm not sure what your issue is here. Can you restate the question?
The functionality of the up one level button has been superceded by the new
breadcrumb bar in Windows Explorer. You cannot add the up one level button
to the toolbar.
You can click on any element in the breadcrumb bar to easily go up one, two,
or more levels in a single click.
For example, if you are looking inside the Windows folder, you can click on
up two levels.
For even more versatility, you can click on the arrows between elements on
the breadcrumb bar to quickly navigate to a subfolder of that element.
For example, clicking the arrow to the right of "Local Disk (C:)" will allow
you to navigate to one of the folders contained in that drive, Program Files
You can still press the backspace key to go up one level.
Many folders used by earlier versions of Windows have been moved to a new
location or given a new name in Windows Vista. However, the old folders can
still be seen if you have enabled Show Hidden Files.
Notice they are displayed with a transparent icon and a shortcut symbol.
Although these look like folders, they are actually what is known as a
junction. Junctions behave like shortcuts, but look just like regular
Their purpose is to silently redirect programs that access them to their
Windows Vista equivalent.
Any attempt to access them will give you an "Access Denied" error. You
should find the new location and use it instead.
You're welcome :)
Microsoft MVP - Windows Shell/User
Windows Vista Support Faq