Interesting.. You said you couldn't run tag on XP. It runs on mine just fine... However, the juiciest bit of news, from the TAG page, is:

Tag is released as freeware. Use at your own risk.
ID3v2 support with id3lib, which requires msvcp60.dll to function.

"support with id3lib".. That mean if I have the DLL file, it will write v2 tags? Or does that mean the "reading and removing" onl;y with the library? Too many unanswered questions. Erf.