OK, then this should work: search your computer and find out if there any
.itl files on your computer and, if there are, make a note where they're located. If you haven't changed iTunes default settings, you should find one at
C:\Documents and Settings\User Name\My Documents\My Music\iTunes .Then connect iTunes to that file by using the
Choose Library option that is described in
http://support.apple.com/kb/HT1589 in the Apple Knowledge Base.
Let me know if that helped you.