Can't access iTunes after OS Reload

Hi, I recently had to reload my Mac OS after replacing the hard drive. I started by installing 10.3.9 and eventually upgraded all the way to 10.4.11. I also did all the software updates. Everything went well except when I tried to launch iTunes the message "The iTunes library cannot be read because it was created by a newer version of iTunes". I noticed that the version currently installed is 6.0.4. I suspect that pre-crash I had updated iTunes to a newer version, but I have no way of checking. In any case how can I upgrade ay to 7.0.2 if that is the version I need. So my questions are: How can i tell what version iTunes the library was created on and then how do I upgrade to the correct version? I really only use iTunes to load music onto my iPod and to play music from the iTunes library that I have loaded over the years. I can see the music files in there but I can lauch iTunes to play them. Hope someone can help me on this.