iTunes won't import files in Win7/64-bit

I have just installed Windows7 64-bit Professional on my computer. Totally clean install (no upgrade...deleted partitions, reformatted etc...totally clean install). Previously, this computer had Win XP 32-bit, running iTunes successfully for years.

All of the media files I am attempting to import were ripped in iTunes, so I *KNOW* they're iTunes friendly.

I can't get any of my media files (MP3's, MP4's...) to import. Dragging & dropping does nothing. File>Add File To Library does nothing. File>Add Folder to Library appears to *start* an import process, but it fails shortly after with no explanation.

I also tried creating a new iTunes library, but the behavior is the same.

When I add content from iTunes Store, it is added to the database no problem.

I have tried running iTunes in Compatibility mode (tried XP/Vista both...) with no luck. I have told it to run with Admin privileges...with no luck. I have 'repaired' iTunes...with no luck. I have uninstalled / reinstalled iTunes...with no luck.

I am running out of ideas. Any suggestions out there? I can't believe that the media files have all gotten corrupt in the 24 hours since I had XP on this machine. HELP!!