I’ve now received exactly two messages regarding the warnings issued by iTunes — you know, the ones that pop up every so often that contain the small “Don’t warn me again” checkboxes — and it is therefore time to act. Those checkboxes are the issue. Specifically, once you check the thing, how do you undo that action and force those warning dialog boxes to appear again?
The current version of iTunes allows you to reset iPod and Store warnings. To reset iPod warnings, simply Control-click (Mac) or Right-click (Windows) on an iPod in iTunes’ Source list and choose “Reset Warnings.” To reset Store warnings, move to your iTunes Store Account Information window (do this by selecting iTunes Store in the Source menu, clicking your account name in the upper right corner, and entering your Apple ID when prompted in the resulting dialog box) and click Reset Warnings where it says “Reset All Warnings for Buying and Downloading Music” at the bottom of the window.
Regrettably, iTunes doesn’t include an option to restore the program’s other warnings. To do so, you must quit iTunes and then delete iTunes’ preferences file (and no, doing so won’t cause your songs or playlists to disappear).
To delete iTunes preferences on a Mac, travel to youruserfolder /Library/Preferences and delete the com.apple.iTunes.plist file.
In Windows, move to C:Documents and Settings yourusername Application DataApple ComputeriTunes and delete the iTunesPrefs file.