This is the official page, from which you can download the Official Viwa V4 Stock Firmware ROM (flash file) on your Computer. The Firmware Package comes as a zip file which contains the Firmware, Flash Tool, Driver and How-to Flash Guide.
Download Viwa V4 Stock ROM (flash file)
Package Name: Viwa_V4_20150706_OTA.zip
Package Size: 411 MB
How-to Flash: Copy the update.zip file to the phone SD and flash it through the stock recovery mode.
Download Link: Click Here to Start Download
How to Flash Viwa V4 Stock ROM
Step 1: Download and Extract the Viwa V4 Stock Firmware on your Computer.
Step 2: Once, you have extracted the Package, you will get the update.zip firmware and How-to Flash Guide.
Step 3: Now, Copy the update.zip firmware on your device SD memory.
Step 4: Once you have copied the update.zip firmware, Power Off your device.
Step 5: Now, boot into the recovery mode by pressing Volume UP + Power Button.
Step 6: Once, you have booted into the recovery mode, select the update.zip firmware to flash it.
Step 7: Once flashing is completed, restart your device.
[*] Original firmware: We only Serve the original firmware which is released by the company and we scan each of our firmware with Eset Internet Security before uploading it online.
[*] Backup: We recommend you to take a backup of your personal data before flashing the Stock Firmware, as flashing the firmware delete the personal data from the device.
[*] Caution: We do NOT recommend you to Flash the Preloader.bin. As it may brick the device, therefore we recommend you to Untick the Preloader which Flashing in on your device.