Backing up your device stock ROM before flashing or tempering with your mobile is quite essential. Today I will teach you how to backup and restore your stock ROM via CWM recovery.
Guess you already have a recovery flashed, reboot to recovery by holding the power button and up volume button at the same time, navigate to backup and restore using the volume down button, click on it using the power button.
NOTE: there are 6 options there's namely..
(1). Backup (To backup to sdcard)
(2).Restore (To restore from sdcard)
(3). Advanced restore (To restore specific file like boot.img in sdcard)
(4). Backup to internal storage
(5). Restore from internal storage
(6). Advance restore from Internal storage.
Now click on backup and it will start backing up to sdcard or you can click on backup to internal storage depending on were you have sufficient space. Make sure it says backup complete before going further to flash a ROM. If it gives any error, then free some space and backup again.