The iTunes 12 app installed on a Windows 10 PC may have the backup data you copied from an iPad tablet due to low storage. You can manually paste the iTunes backup when your iPad has more free space. Manually synchronizing the data can be tried via iTunes 12 to sync the backup with the device, and that is quite easy to do with an Apple Lightning cable.
First, launch iTunes from the Start Menu of Windows 10 and connect the iPad tablet to the Windows PC with the Apple Lightning cable. Once the device is recognized by the app, click on the Device button – in this case, iPad icon.
Choose Music on the left-side menu of iTunes and put a checkmark next to the Sync Music option. Once you select that, you can check Movies, Music, and Photos to synchronize. Click on Apply followed by Sync to synchronize the data containing in iTunes with the iPad tablet.
You can also set up data sync in between iCloud and the iOS with Wi-Fi and no Lightning cable is required for that. You may have stored a set number of movies, music, and other data on iCloud and you certainly can restore the same to iPad.
To do that, launch a browser on Windows 10 PC, navigate to www.support.apple.com/en-ca/HT204283, and then click on Download. Then, click on the Save button to download iCloud for Windows 10. Once the download finishes, Run the setup, click on I Accept the Terms, and choose Install. Once the installation of iCloud finishes on the Windows 10 PC, click on Finish. Then, the Windows 10 PC will restart, and upon restarting, the iCloud window would pop-up automatically on the screen.
Enter your Apple ID and Password and sign in to iCloud. Put a checkmark next to iCloud Drive and repeat the same to sync Photos, Contacts, Calendars, and Tasks and Bookmarks. Once you put a checkmark next to each data you have backed up on iCloud Drive, click on Apply to sync.
After you upgrade the iOS on a refurbished iPad, you can restore the backup data via iCloud or iTunes either through Wi-Fi sync or manually. Choose the one based on convenience and available storage space.