Hi,
I found some apps which can auto-tag from web the song files.
Please make one of these applications portable:
Winamp
MusicBrainz Picard ("GPL2 or later" http://musicbrainz.org/doc/MusicBrainz_Picard bottom of page)
Foobar
MediaMonkey
Jaikoz(But need to purchase a license, do not make it portable!)
Note for Winamp:
WinampPortable is beta at the moment and it does not include auto-tag feature. Winmap asks on installation to end-user if he wants to install autag feature or not (http://nunzioweb.com/images/winamp/auto-tag-support.png). But WinampPortable does not asks. So WinampPortable should re-build again by including it.
The best auto-tagger is Winamp. I tried many times...
Thank you!