How to fix iTunes Error 54 and recover data?

Do you have ever encountered such case that an unknown error occurs on your computer when syncing your iPhone with iTunes? If you want to successfully sync your iPhone with iTunes, you should know why this error occurs.
Why the iTunes sync 54 error occurs?
Error 54 is one of the common iTunes problems when you sync your iPhone with iTunes on your new Windows operation system. This error refers to permission and administration issues. That may for you have not authorized your computer, or you are not the person who has permission to modify or move the data.
Here are the solutions that you can try to deal with this error:
1. Authorize your computer to use iTunes. You can open iTunes and choose Store to authorize your computer.
2. You should sign in your computer as an administrator.
3.  Update your iTunes and iPhone to latest version.
4. Check the permission of your iTunes folder on computer. Go to Windows explorer>Music>iTunes folder>Properties> uncheck “Read Only”.
5. Consolidate the media files in your iTunes library.
6. Check if there are third-party software interfere with the sync process.
In case you have tried all the ways but still cannot sync iPhone with computer, you can try other alternative ways. For example, you can back up your data on iPhone to iCloud account, which do not need any app, USB cable and computer. If you recently lost some data on your iPhone, and you cannot restore from iTunes, you still can use an iPhone data recovery software to scan and retrieve the lost data.
How to recover data from iPhone after data loss?
If you failed to sync your iPhone with computer, you cannot directly restore backup to iPhone in iTunes, you have three ways: recover from iCloud, recover from iPhone with data recovery program, or extract data from iTunes backup on computer.
iTunes backup contains all your data but they cannot directly read on computer, so you should use an iPhone recovery software to restore all the data.
Install H Data iPhone recovery software on computer which your iTunes backup stays in.
Run H Data iPhone recovery software and choose “View and Restore from iTunes backup”.
Choose the iTunes backup that you need to restore.
Click “Scan” button to let it scan the data in iTunes backup.
After scan, you can preview all the existing data in iTunes. The deleted data are display in red.
Tick all the data you need and click to export your selected records. The recovered data will be restored to a recovery folder, you will find the data you need here.