Note
Device must be rooted & CWM recovery installed.
Make sure there is about 2GB of memory in your device SD card.
No file is lost or changed after this procedure.
Download MTK Droid Tools from here
Download android adb drivers from here or here
Learn how to root your device from here.
Learn to install CWM from here
Launch MTK droid tools.
Boot device into CWM recovery by holding volume up and power button for about 3secs.
Connect device to PC and wait for MTK droid tools to detect it.
The small square in cyan color shows phone is booted in CWM recovery.
Click on backup, root, recovery tab.
Click Backup button and wait for the ROM ro back up. This will take about 15mins.
When Back up is complete, navigate to backups inside MTK droid tools folder.
You will see a folder with name of the device you just backed up.
Open MTK droid tools in the backup, root, recovery tab and click prepare blocks for flash tool
Navigate to backups inside MTK droid tools folder.
Open the folder having the name of your device.
Select files.md5 and wait for the process to complete. This might take 2 - 5 mins.
When it is completed. navigate to the folder having the name of the device.
The ROM back up is found inside the !Files_to_FlashTool folder.
Learn how to flash the backup ROM to a device from here