How do I fix this iTunes library issue it says it cannot be read because it was created by a newer version of iTunes?

How to Successfully Use An Older Version of iTunes

1. After Installing iTunes 7 (or the latest version) go into My Documents/My Music.
2. Now go into the iTunes folder.
3. Rename your iTunes Library.itl as iTunes Library.itl.old.
4. Go into the Previous iTunes Libraries folder (which would be in MyDocuments\MyMusic\Previous iTunes Libraries).
5. Take the newest file (for me this was iTunes Library 2006-09-14.itl) and copy it back up to the iTunes folder.
6. Rename it iTunes Library.itl.
7. Run iTunes 6 and you should be all set, with your library restored

Another user said:

I recently downgraded WinXP to Win2K and received this error after installing iTunes for Win2K. This was the first article I read when I investigated my options. The second step was confusing to me because the "previous library" file did not exist. I simply renamed the old (newer) library with the "itl.old" file extension and that worked.

Also, after you rename the iTunes icons it may not work. To fix that click on 'use web service to find appropriate program' and do the following steps (it does work).