How to navigate a large HDD full of (say...) movies?

Suppose that you have a large HDD full with movies.
(Not that I have any ideas how that can happen...)

Is there a simple way to attach tags to them and navigate/cluster them in some useful ways (possibly with something based on the existing filesystem of the HDD)?
... and for windows XP or above?

This project looks very intersting: ''Windows File Tagger Shell Extensions'' [source], but it is still "under construction" :(

''AudioShell - ID3 tag editor shell extension ... allows you to view and edit ID3 metadata tags directly in Windows Explorer'' [source] Too bad not all video file formats support ID3 tags...

''How to read File Summary Information [in Delphi]'' [source]

Interestingly some people talk about using keywords in XP or even tags of Windows7:
''In XP I was able to edit the meta data in almost any file and place "keywords" even on PDF files. Windows 7 has done away with "keywords" and gone to "tags". I like this system better but what I find horribly frustrating is that there are many file types to which I cannot add "tags".''[source]