Hi Shaan_0511,
If there isn't a recent backup of your iPhone in iTunes and you choose to restore from an older backup, some data may not be restored.
These articles and excerpts from them should help you better understand Resetting the Sync History and creating a current backup.
iTunes 11 for Windows: iTunes Devices preferences
http://support.apple.com/kb/PH12470
Reset Sync History |
If you’re having trouble syncing your iPhone or iPod with iTunes, resetting your sync history might solve the problem. Selecting this option won’t delete any synced information, but the next time you sync, you may be asked to merge or replace information. |
iOS: Back up and restore your iOS device with iCloud or iTunes
http://support.apple.com/kb/ht1766
To back up the content on your iOS device, follow these steps:
- Make sure your computer has the latest version of iTunes.
- Connect your iOS device to your computer.
- Choose File > Devices > Back up.
If you're using iTunes 10.7 or earlier, right-click the device from the list and choose Backup Now.
You can also back up by syncing your iOS device with your computer. When you use iTunes to sync, backing up is the first step.
To verify that the backup finished successfully, open iTunes Preferences and select the Devices tab. You'll see the name of the device along with the date and time iTunes created the backup.
-Jason