backup應該無影響
最保險做法就去directory copy多一次個backup folder
Search for the backup folder on Windows
1. In the address bar, enter %appdata%. If you don’t see your backups, enter %USERPROFILE%.
2. Press Return.
3. Double-click these folders: "Apple" or "Apple Computer" > MobileSync > Backup.
成個folder抄落其他地方
裝完新itunes再去呢度check下
如果見冇咗就抄返落去