Hi, welcome to Apple Discussions.
Which article? Post a link and it might be easier to guess where you could have gone wrong. Did you copy the files or move them? If you've moved them by accident you should be able to copy them back to where they used to live. Once you've fixed things here is my suggestion for backing up...
*Fast backup for iTunes library (Windows Only)*
Grab
SyncToy 2.0, a free tool from MS. This can copy your entire iTunes library & any other media folders onto another hard drive or network share. You can then use SyncToy periodically to synchronise or echo your library to the backup. A preview will show which files need to be updated giving you a chance to spot unexpected changes and during the run only the changed files will be copied saving lots of time.
tt2