file names missing under icons in Explorer

A friend's desktop machine (running under Vista) has suddenly started
omitting the file names under the icons in Windows Explorer.

I discovered that if you right click in the white pane and select view you
can take the tick out of the 'Hide file names' box - although sometimes it
only appears if you hold the shift key down.

The problem is that somehow it has been set as a default because every
folder and subfolder does not display the file names unless you go through
the procedure above, which is very tiresome.

Is there a way to reset the default to always show the filenames?

Thanks for any help,

Noel