iTunes writes the Comment to the File. It is stored in the ID3v2 "Comment" tag. If there is anything in the ID3v1 tag, iTunes does not see it.
If your file has a Comment in iTunes, a backed-up copy will have the same Comment if used elsewhere in iTunes.
If you have a program on your computer that can see both the V1 and v2 tags, such as Winamp, you will see that iTunes only uses the v2 tags. Windows may handle the file differently, but that does not matter to iTunes. Your backup with the Comment should still be fine.
You are correct that iTunes does not write Ratings to the file. Rather, ITunes stores this information in the library file, and it will not transfer unless you have the complete library.
hi, thanks so much for your help - I'm trying hard to get on top of this but not there yet - could you clarify?
until recently, I stored various text details in the iTunes comments field for thousands of MP3s
then I discovered to my horror that the comments field reappeared in Windows as gibberish - apparently, 8-digit numerical code - are you saying that if I find and delete all the ID3v1 tags, Windows will get to see the comments fields as I created ithem? ... if so, how to do?
and re the ratings, you say "ITunes stores this information in the library file, and it will not transfer unless you have the complete library" - could you spell out how to ensure my ratings reappear in Windows - maybe copying them to another field?
thanks again, much appreciated
I haven't tried that but you could experiment with a track or two, using iTunes to convert its tags to v1 format, and see what Windows does with them. This is accomplished by right-clickin the library entry and choosing "Convert ID3 Tags..." When the dialog comes up, pick 1.0 or 1.1. Then use the revised file in Windows and see if it is what you want.
As far as Ratings, iTunes is the Roach Motel. They are stored in the iTunes library file, not in the individual songs. There may be a script out there that can extract them and put them into the individual file for use in other programs, although I do not know of one.