1。 Did the landlord download itunes? If yes, open itunes first, then click Store in the upper right corner, and you will see that this computer is authorized (English version is Authorize this computer), and then a dialog box will appear, telling you that only five computers can be authorized. Just click "Yes".
2. You can't use the format of ipod. Apple has a clear rule that it must be in its specified format, otherwise itunes will not be synchronized, such as
Audio support: AAC (16 to 320 Kbps), protected AAC (from iTunes Music Store), MP3 (16 to 320 Kbps), MP3 VBR, Audible (2 2,3,4 formats), Apple Loss, WAV, AIFF.
Picture support: Synchronize pictures in JPEG, BMP, GIF, TIFF, PSD (Mac only) and PNG formats, which can be viewed through iPod.
Well, that's the end of the answer. If the landlord has any dissatisfaction, you can continue to ask. Finally, I wish the landlord a happy day. O(∩_∩)O~